JP4188974B2 - Semiconductor integrated circuit - Google Patents

Description

  The present invention relates to a semiconductor integrated circuit device, and more particularly to a semiconductor integrated circuit device excellent in high-speed and low-power operation characteristics.

  Minimize the chip manufacturing process as described in “Deep-Submicron Microprocessor Design Issues”, IEEE Micro, pp. 11-22, July / Aug., 1999 to integrate many functions on the chip. It is generally done. By miniaturization, the number of MOS transistors that can be integrated on a chip can be increased, thereby realizing many functions in one chip.

“Deep-Submicron Microprocessor Design Issues”, IEEE Micro, pp. 11-22, July / Aug., 1999

  Many circuits can be integrated on a chip by miniaturizing the chip. However, a large design man-hour is required to integrate many circuits on a chip with a sufficiently small defect rate. As a result, the chip development period becomes longer. On the other hand, when a large design man-hour is used to shorten the development period, human resources for design are under pressure, which hinders the development of many varieties. In order to cope with such a problem, it is considered to divert already developed circuit blocks to various kinds of chips.

  On the other hand, as described in “Identifying defects in deep-submicron CMOS ICs”, IEEE Spectrum, pp. 66-71, September, 1996, leakage current (leakage current is not included in the manufacturing process of chips). It is known that subthreshold leakage current, gate tunnel leakage current, junction leakage current such as GID (Gate-Induced Drain Leakage) current increases). Those leakage currents increase the current consumption of the chip. By controlling the power supply voltage of the circuit during standby, the current consumption of the chip due to these leakage currents can be reduced.

  However, when the power supply voltage of the circuit block is cut off during standby, the output node of the circuit block is in a floating state. Therefore, a through current flows in the circuit block that receives the output from the output node. For this reason, when diverting a circuit block for controlling the power supply voltage, it is necessary to redesign an interface for preventing a through current. This may prevent diversion of the circuit block with reduced power.

  A first circuit block; a second circuit block; and a conversion circuit connecting the first circuit block and the second circuit block. The first circuit block includes a first mode and a power supply voltage to which a power supply voltage is supplied. When the first circuit block is in the second mode, the conversion circuit sets the potential of the input node of the second circuit block to any of the operating potentials of the second circuit block. Try to control it. In particular, the conversion circuit is a circuit having a predetermined power supply control interface. When connecting each circuit block, the conversion circuit is connected via the conversion circuit.

  Further, power supply lines are provided so as to circulate around the circuit block, and the power supply control circuit is arranged by appropriately using the region where these power supply lines are arranged.

  The main effects of the present invention are as follows. The number of man-hours required for module development can be reduced, and circuit block changes accompanying changes in the manufacturing process can be minimized. In addition, an optimum power supply voltage can be supplied to each circuit block, and an improvement in operating speed and a reduction in power can be realized simultaneously. Furthermore, power supply can be cut off by various means when the circuit block is not used, and unnecessary power consumption due to leakage current or the like can be minimized.

<First Embodiment>
FIG. 1 shows a basic configuration of the present invention. The circuit blocks BLK1, BLK2 are composed of one or more MOS transistors. In this specification, the word MOS transistor is used as a general term for an insulated gate field effect transistor. The circuit block BLK is preferably configured as a CMOS circuit in which a P-type MOS and an N-type MOS are connected in series. Here, the circuit block BLK1 has a mode in which the power supply voltage is controlled to reduce leakage current independently of turning on / off the power supply to the entire chip CHP1 (the circuit block BLK2 may have a similar mode). ). Micro I / O MIO1, MIO2, MIO3, and MIO4 are characteristic configurations of the present invention, and detailed configurations thereof will be described later. The I / O buffers IOB1 and IOB2 are output from the low-impedance output driver circuit DRV1 for driving a large load capacity outside the module MDL1, or the input buffer circuit IBF1 to which an electrostatic breakdown prevention element is added if necessary. It is configured. I / O buffers MIOB1 and MIOB2 have low impedance to drive a relatively large load capacity outside chip CHP1 (inside module MDL1) (however, higher impedance than output impedance of output driver circuit DRV of IOB buffer IOB) Output driver circuit DRV2, and an input buffer circuit IBF2 to which an electrostatic breakdown preventing element is added if necessary. In this specification, when distinguishing an I / O buffer for connecting chips in a module from an I / O buffer for connecting modules, the term “mini I / O buffer” is used. I will call it. L11, L12, L13, L21, L22, L23, L24, L31, L32, L41, L42, and L43 indicate signal line groups.

  The chip is a semiconductor integrated circuit device using one semiconductor substrate, and the module is a semiconductor integrated circuit device configured by using one or a plurality of these chips. As an example of the module, there is a form in which a plurality of chips are mounted in one package, such as a stacked CSP (Stacked Chip Scale Package) and an MCP (MultiChip Package). As another example, there is a form in which a plurality of packages are mounted on a printed circuit board, such as MCM (Multi Chip Module) and SIMM (Single Inline Memory Module) widely used in dynamic memory.

  The signal line group L41 of the circuit block BLK1 is connected to the I / O buffer IOB1 by the signal line group L42 via the micro I / O MIO1, and is connected to the outside of the module MDL1 by the signal line group L43. The signal line group L32 of the circuit block BLK1 is connected to the circuit block BLK2 by the signal line group L31 via the micro I / O MIO4. The signal line group L11 of the circuit block BLK2 is connected to the I / O buffer IOB2 by the signal line group L12 via the micro I / O MIO2, and is connected to the outside of the module MDL1 by the signal line group L13. The signal line group L21 of the circuit block BLK2 is connected to the mini I / O buffer MIOB1 by the signal line group L22 via the micro I / O MIO3, and the chip in the same module as the chip CHP1 by the signal line group L23. It is connected to the mini I / O buffer MIOB2 in CHP2.

  Each of the signal line groups L11, L12, L21, L22, L31, L32, L41, and L42 includes a signal line group specific to a circuit (circuit block, I / O buffer) and a power supply control interface signal line group. The signal line group specific to the circuit is not particularly limited, but includes a data signal line, an address signal line, and the like. Details of the power control interface signal line group will be described later.

  FIG. 2 shows another configuration example. The circuit block BLK1 is a circuit block having the same function as the circuit block BLK1 in FIG. 1, MIO1 and MIO4 are micro I / O, and IOB1 and IOB3 are I / O buffers. CHP3 is a chip and MDL2 is a module. The signal line group L41 of the circuit block BLK1 is connected to the I / O buffer IOB1 by the signal line group L42 via the micro I / O MIO1, and is connected to the outside of the module MDL2 by the signal line group L43. The signal line group L32 of the circuit block BLK1 is connected to the I / O buffer IOB3 by the signal line group L31 via the micro I / O MIO4, and is connected to the outside of the module MDL2 by the signal line group L33.

  In the present invention, each circuit block communicates with the outside of the circuit block via the micro I / O. Therefore, in both the configuration examples of FIGS. 1 and 2, the connection destination of the circuit block BLK1 is the micro I / O. Because the connection destination is the same, the same circuit block BLK1 is used to configure separate chips or modules as they are without changing the interface specifications related to power control of the circuit block as shown in FIGS. can do. Thereby, the man-hours required for module development can be greatly reduced. This is possible even if the manufacturing processes of the chip CHP1 of FIG. 1 and the chip CHP3 of FIG. 2R> 2 are different, and the change of the circuit block accompanying the manufacturing process change can be minimized. Specifically, it is assumed that the chip CHP3 in FIG. 2 is a chip manufactured by a CMOS process of 0.18 μm. On the other hand, a 0.13 μm CMOS process is applied to the chip CHP1 of FIG. Since this process miniaturization allows many circuits to be integrated even in the same chip area, the circuit block BLK2 is also integrated in the chip CHP1 in addition to the circuit block BLK1. In this way, when developing a new chip by diverting an already developed circuit block to another chip, if each circuit block is designed to be connected to the outside via micro I / O, the diversion is used. This eliminates the need for additional development of a power supply control interface for the circuit block to be performed. Therefore, the correction of the circuit block accompanying the process miniaturization can be minimized.

  Also, if the chip is different, the communication destination of the circuit block via the micro I / O may change. For example, the connection destination of the signal line group L31 of the circuit block BLK1 differs between FIG. 1 and FIG. In the configuration example of FIG. 2, the signal line group L32 is finally connected to the outside of the module MDL2 via the signal line group L31. On the other hand, in the configuration example of FIG. 1, the signal line group L32 is finally connected to the circuit block BLK2 on the same chip CHP1 via the signal line group L31. Even if the communication destination of the circuit block via micro I / O changes as the chip / module configuration changes in this way, I / O buffers, mini I / O buffers, etc. are connected to the micro I / O. Can be configured. If the communication destination is on another chip in the same module, it is only necessary to drive a relatively small load capacity, so use a mini I / O buffer, and if the communication destination is in another module, compare Since it is necessary to drive a large load capacity, an I / O buffer may be used. Furthermore, when the communication destination is in the same chip, there may be no I / O buffer or mini I / O buffer, or a buffer having a driving force smaller than that of the mini I / O buffer may be connected. . Due to the presence of the micro I / O, the buffer to be used can be freely selected according to the communication destination, and the interface can be increased in speed and power consumption.

  FIG. 3 shows the basic configuration of the present invention. The circuit block BLKA and the circuit block BLKB are connected by signal line groups LA and LB via a micro I / O MIO. In general, a circuit block is a group of circuits having a certain function that can be shared among many modules. IP (Intellectual Property: a group of circuits in units of functional units such as arithmetic functions and signal control functions provided in a semiconductor integrated circuit) supplied by a so-called IP provider is also included. A circuit block in which the micro I / O of the present invention is preferably used is a circuit block that is a unit of power control. For example, it is assumed that the circuit block BLKA can supply / shut off power independently of power on / off for the entire chip. In the case where power supply to the circuit block BLKA is cut off and power is supplied to the circuit block BLKB, the signal line from the circuit block BLKA to the circuit block BLKB is in a floating state, and the circuit block BLKA and the circuit block BLKB are temporarily Is directly connected to the circuit block BLKB to which power is supplied. By using the micro I / O, it is possible to easily prevent adverse effects on the operation of the circuit block BLKB due to the power control of the circuit block BLKA.

  In the above example, the circuit block BLKB may also be a circuit block that can supply / shut off power independently of power on / off for the entire chip. Further, the circuit block BLKA and the circuit block BLKB may be circuit blocks that operate at different operating voltages. For example, the I / O buffers IOB1, IOB2, and IOB3 and the mini I / O buffers MIOB1 and MIOB2 shown in FIGS. 1 and 2 are also a type of circuit block.

  In the present invention, as described above, the interface between one circuit block BLKA and another circuit block BLKB is structured to be performed via a micro I / O. When the power supply voltages of the circuit block BLKA and the circuit block BLKB are different, signal amplitude conversion (hereinafter referred to as level conversion) is required between them. FIG. 4 shows a basic configuration example of the present invention including the micro I / O shown in FIG. 3 in the case of having a level conversion function. VDDA and VSSA indicate the power and ground of the circuit block BLKA, and VDDB and VSSB indicate the power and ground of the circuit block BLKA. Note that the power supply voltage supplied to the circuit is defined as a high potential and a low potential, but these terms are used to represent a high potential for the power supply and a low potential for the ground. The signal lines d1 and d3 represent one bit of the signal line group between the circuit block BLKA and the circuit block BLKB as a representative. Here, a signal from the circuit block BLKA on the transmission side is output through the signal line d1, and is input to the circuit block BLKB on the reception side through the signal line d3 via the micro I / O MIO. Micro I / O consists of a two-stage circuit, a micro I / O pre-stage circuit MIOA that operates between the power supply VDDA and the ground VSSA, and a micro I / O post-stage circuit MIOB that operates between the power supply VDDB and the power supply VSSB power supply. Has been. A signal line d2 indicates a plurality of signal line groups between the micro I / O pre-stage circuit MIOA and the micro I / O post-stage circuit MIOB. The signal d1 of the signal amplitude (VDDA-VSSA) output from the circuit block BLKA is input to the micro I / O pre-stage circuit MIOA, and the micro I / O pre-stage circuit MIOA transmits the signal necessary for level conversion through the signal line group d2. The micro I / O post-stage circuit MIOB is input to the I / O post-stage circuit MIOB, and is converted into a signal amplitude (VDDB-VSSB) signal and input to the circuit block BLKB through the signal line d3.

  With this configuration, an optimum power supply voltage can be supplied to each circuit block, and an improvement in operating speed and a reduction in power can be realized simultaneously. For example, circuit blocks such as I / O buffers, mini I / O buffers, real-time clock (RTC), interrupt processing circuits, DRAM refresh circuits, and low-speed / large-capacity memories are supplied with relatively high power supply voltages. What is necessary is just to enlarge the absolute value of the threshold voltage of the MOS transistor which comprises. Since these circuit blocks have a relatively low activation rate, power consumption by a DC current such as a subthreshold leakage current is dominant, but power consumption by the DC current can be reduced. On the other hand, a relatively low power supply voltage is supplied to circuit blocks such as a CPU, MPEG4 accelerator, and high-speed / small-capacity memory, and the absolute value of the threshold voltage of the MOS transistors constituting these circuit blocks may be reduced. . In these circuit blocks that require high-speed operation, current consumption due to charge / discharge current is dominant, but it can be efficiently reduced.

  Note that the threshold voltage and the gate insulating film thickness of the MOS transistors constituting the circuit block may be appropriately set according to the power supply voltage supplied to the circuit block and the required operation speed. It is not limited to a single size within a chip or module.

Next, the configuration and operation of the micro I / O will be described by taking as an example a case where the operation voltages of the circuit block BLKA and the circuit block BLKB as shown in FIG. 4 are different. In order for the micro I / O to operate normally, it is necessary that a through current does not flow even when a floating signal line is input. Consider the following four power supply interruption patterns.
(1) When the power supply of the circuit block BLKA on the transmission side and the power supply of the micro I / O pre-stage circuit MIOA are interrupted (when the potential supply to VDDA or VSSA is interrupted). This state is referred to as “power cutoff case 1”.
(2) The power supply to the circuit block BLKB on the receiving side is cut off (the potential supply to VDDB or VSSB to the circuit block BLKB is cut off), while the power supply to the micro I / O post-stage circuit MIOB is carried out If yes. This state is referred to as “power cutoff case 2”.
(3) The power supply of the circuit block BLKA on the transmission side is cut off (the potential supply to VDDA or VSSA to the circuit block BLKA is cut off), while the power supply of the micro I / O pre-stage circuit MIOA is carried out If yes. This state is referred to as “power cutoff case 3”.
(4) When the power supply of the circuit block BLKB on the receiving side and the power supply of the micro I / O post-stage circuit MIOB are interrupted (when the potential supply to VDDB or VSSB is interrupted). This state is referred to as “power cutoff case 4”.

  In the case of the power cutoff case 4, basically the micro I / O operates normally with the configuration example of FIG. 4R> 4. Since the power supply to the circuit block BLKB on the receiving side and the post-stage circuit MIOB on the micro I / O is cut off, the circuit block BLKB or the micro I / O on the receiving side regardless of whether the power is supplied to the circuit block BLKA on the transmitting side. This is because no through current flows through the subsequent circuit MIOB. A configuration example of a micro I / O for supporting the power shutdown cases 1 to 3 is shown below.

  FIG. 5 shows a configuration example in which the micro I / O operates normally in the power shut-off case 1. The power cutoff case 1 can be performed by, for example, a regulator that supplies a potential (VDDA, VSSA, VDDB, VSSB) to the chip shuts off the supply of the potential VDDA or the potential VSSA. In the configuration example of FIG. 5R> 5, the signal line e is input from the circuit block BLKB on the receiving side to the micro I / O post-stage circuit MIOB. In the power cutoff case 1, since the power supply to the micro I / O pre-stage circuit MIOA is cut off, the signal lines output from the micro I / O pre-stage circuit MIOA in the signal line group d2 are in a floating state. Even if the signal in the floating state is input to the micro I / O post-stage circuit MIOB, it is necessary to prevent a through current or the like from flowing through the micro I / O post-stage circuit MIOB. In FIG. 5, in order to realize the normal operation of the micro I / O, the signal line e is input to the micro I / O post-stage circuit MIOB. Therefore, the circuit block BLKB needs to recognize the interruption of the supply of the potential VDDA or the potential VSSA. For example, the specification of the circuit block BLKB may include a content “notify when the supply of the potential VDDA or the potential VSSA is cut off”. Alternatively, the chip may have a plurality of modes, and supply of the potential VDDA or the potential VSSA may be cut off in the specific mode. In this case, when the chip enters the specific mode, the circuit block BLKB can recognize the interruption of the supply of the potential VDDA or the potential VSSA. The circuit block BLKB on the receiving side detects the power supply interruption of the circuit block BLKA on the transmitting side, and sends it to the micro I / O downstream circuit MIOB using the signal line e, so that the micro I / O operates normally. Let

  FIG. 6 shows a configuration example in which the micro I / O operates normally in the power cutoff case 2 in addition to the power cutoff case 1. The power cutoff case 2 can be performed, for example, by blocking the supply to the circuit block BLKB while supplying the potential VDDB or the potential VSSB from the regulator. In the configuration example of FIG. 6, the power supply to the circuit block BLKB is supplied as it is, but the ground VSSB is supplied via the power switch PSWB. The power switch PSWB is turned on / off by the power switch control circuit PSCB. When the power switch control circuit PSCB controls the power switch PSWB to turn off, the power shut-off case 2 is brought about. When the power shut-off case 2 occurs, the signal line e enters a floating state. Therefore, when the power switch control circuit PSCB controls to turn off the power switch PSWB, it notifies the micro I / O post-stage circuit MIOB using the signal line cr. Since the micro I / O post-stage circuit MIOB can detect the floating state of the signal line e by the signal line cr, the micro I / O can operate normally.

  FIG. 7 shows a configuration example in which the micro I / O operates normally in the power cutoff case 3 in addition to the power cutoff case 1. The power shut-off case 3 can be performed, for example, by blocking the supply to the circuit block BLKA while supplying the potential VDDA or the potential VSSA from the regulator. In the configuration example of FIG. 7, the power supply VDDA is supplied as it is to the circuit block BLKA, but the ground VSSA is supplied via the power switch PSWA. On / off of the power switch PSWA is controlled by a power switch control circuit PSCA. When the power switch control circuit PSCA controls the power switch PSWA to be turned off, the power shut-off case 3 is brought into a state. When this power cut-off case 3 occurs, the signal line d1 enters a floating state. Therefore, when the power switch control circuit PSCA controls to turn off the power switch PSWA, it notifies the micro I / O pre-stage circuit MIOA using the signal line cs. Since the micro I / O pre-stage circuit MIOA can detect the floating state of the signal line d1 by the signal line cs, the micro I / O can operate normally.

  FIG. 8 shows a configuration example in which the micro I / O operates normally in the power cutoff case 2 and the power cutoff case 3 in addition to the power cutoff case 1. What is necessary is just to comprise as a combination of the structural example of FIG. 6 and FIG. 7, and detailed description is abbreviate | omitted here.

  FIG. 9 is a more detailed configuration example of the micro I / O of FIG. NAND1 is a 2-input NAND circuit, INV1 and INV2 are inverter circuits, AND1 is a 2-input AND circuit, MP1 is a PMOS transistor, and MN1 is an NMOS transistor. LC1 is a level conversion circuit that amplifies or attenuates the signal amplitude (VDDA-VSSA) of the input signal (d2, / d2) and outputs it to d4 in accordance with the power supply voltage amplitude (VDDB-VSSB) of the level conversion circuit LC1 To do. The logic level output to d4 is the same as the logic level input as d2. As for the power supply of the level conversion circuit LC1, the power supply VDDB is supplied as it is, but the ground VSSB is supplied via the NMOS transistor MN1.

  In the case of the power shutoff case 1, the NMOS transistor MN1 is turned off and the PMOS transistor MP1 is turned on by setting the signal line e to the “L” level. Therefore, even if the signal lines d2 and / d2 are in the floating state, the NMOS transistor MN1 in the off state prevents the through current from flowing through the level conversion circuit LC1. Further, at this time, the output level of the level conversion circuit LC1 is in a floating state, but since the logic level of the signal line d4 is fixed to the 'H' level by the PMOS transistor MP1, the micro I / O can be normally operated. it can.

  In the case of the power shutdown case 2, by setting the signal line cr to the “L” level, even if the signal line e is in a floating state, the through current does not flow through the AND circuit AND1, and the output level is also the “L” level Therefore, the micro I / O can be operated normally.

  In the case of the power shutdown case 3, by setting the signal line cs to the “L” level, even if the signal line d1 is in the floating state, no through current flows through the NAND circuit NAND1, and the output level is also the “H” level. Therefore, the micro I / O can be operated normally.

  FIG. 19 shows a configuration example of the level conversion circuit LC1. This is a differential level conversion circuit to which a signal d1 and a complementary signal / d1 are input.

  In the configuration examples of FIGS. 4 to 9, the circuit block BLKA communicates with a so-called single-end signal that transmits information for one bit through one signal line d1. On the other hand, when communication is performed with a dual rail signal (the circuit block BLKA transmits the signal d1 and its complementary signal / d1, that is, transmits one bit of information through two signal lines) The micro I / O pre-stage circuit MIOA becomes unnecessary. In the configuration example of the logic gate level circuit in the case of performing communication with the dual rail signal, the micro I / O pre-stage circuit MIOA is deleted from the configuration example of FIG. 9, the signal d1 is the signal / d2, and the signal / d1 is the signal d2. Is equivalent to a circuit that is input to the level conversion circuit LC1. Of course, in this case, the signal line cs is unnecessary.

  The input / output signal relationships in FIG. 9 are summarized as shown in FIG. The logic levels of the signal lines d1, e, cs, cr in the power supply states (ON, OFF1, OFF2) of the transmission side circuit block SND and the reception side circuit block RCV are shown. The power supply state “ON” of the circuit block is a state in which VDDA / VDDB and VSSA / VSSB potentials are supplied. The power supply status of the circuit block “OFF1” means that VDDA / VDDB and VSSA / VSSB potentials are supplied, and micro I / O (in the case of a transmitter circuit block, its pre-stage circuit or in the case of a receiver circuit block, its subsequent circuit The power supply to the circuit block is interrupted by means such as the power switch PSWA and the power switch PSWB. The power supply state “OFF2” of the circuit block is a state where the potential supply of VDDA / VDDB or VSSA / VSSB is cut off, and “*” indicates all states including the floating state. '-' Indicates the state of 'H' level or 'L' level.

  As described above, when the sub-threshold leakage current that cannot be ignored due to the small absolute value of the threshold voltage of the MOS transistor constituting the circuit block flows, or the gate tunnel leakage current that cannot be ignored due to the thin oxide film of the MOS transistor Even when the current flows, the power supply can be cut off according to the state of the power cut-off cases 1 to 4 when the circuit block is not used. As a result, unnecessary power consumption of the module due to leakage current can be minimized. In addition, it is understood that the through current can be prevented from flowing due to the node that is in a floating state by these controls by the micro I / O. The threshold voltage and gate insulating film thickness of the MOS transistor constituting the circuit block and the threshold voltage and gate insulating film thickness of the MOS transistor constituting the power switch are not particularly limited. The power switch needs to obtain a large on current and a sufficiently small off current by controlling the potential of the gate terminal of the power switch. Therefore, it is desirable that the threshold voltage is higher than the threshold voltage of the MOS transistor constituting the circuit block, and the gate insulating film is thicker than the gate insulating film of the MOS transistor constituting the circuit block. Here, the gate insulating film thickness is an effective gate insulating film thickness considering the dielectric constant of the gate insulating film material.

  In the configuration example of FIG. 9, the ground potential supply of the level conversion circuit LC1 is performed via the NMOS transistor MN1, but the present invention is not limited to this method. For some or all of the level converter circuit LC1, in place of using the NMOS transistor MN1, a PMOS transistor is inserted between the power supply VDDB and the level converter circuit LC1. You may comprise.

  Further, in the configuration examples of FIGS. 6 to 8, in order to realize the power cutoff case 2 or the power cutoff case 3, the NMOS transistor PSWA or the NMOS transistor PSWB is installed as a power switch between the circuit block and the ground line. . On the other hand, a PMOS transistor may be installed as a power switch between the circuit block and the power line.

  Furthermore, it is not necessary to have all of the power cutoff cases 1 to 4, and it may be provided as appropriate according to the specifications of the chip or module. If the power shut-off case 1 does not exist, a buffer circuit may be inserted instead of the AND circuit AND1, and after the signal line cr is buffered, it is connected directly to the gate terminals of the NMOS transistor MN1 and the PMOS transistor MP1. If the power shut-off case 2 does not exist, a buffer circuit may be inserted instead of the AND circuit AND1, and after the signal line e is buffered, it is connected directly to the gate terminals of the NMOS transistor MN1 and the PMOS transistor MP1. Furthermore, when the power shut-off case 3 does not exist, an inverter circuit may be inserted in place of the NAND circuit NAND1, the signal line d1 is inverted, and then connected to the signal line / d2 as it is. In addition to this, it is possible to deal with various combinations of power supply cutoff cases.

  For ease of understanding in FIGS. 4 to 9, the signal transmitted and received between the circuit blocks has been described in the case of 1 bit. Usually, signal lines for exchanging signals between circuit blocks exist for a plurality of bits, and control signals e, cr, cs may be provided for the signal lines for the plurality of bits. It is not necessary to provide a control signal for each bit. Normally, the circuit block can transmit and receive, and the circuit block is divided into the transmission side and the reception side. However, the circuit block is only for the sake of easy understanding. 4 to 9, it is assumed that a differential type level conversion circuit is used. However, an inverter type level down circuit may be used, and the operation voltage between circuit blocks may be the same. In this case, a level conversion circuit is unnecessary. Various circuit changes can be made in accordance with such changes.

<Second Embodiment>
FIG. 11 shows an example of the interface configuration of the power switch control circuit PSCA or PSCB of FIGS. The power switch control circuit PSC that controls the power switch PSW controls on / off of the power switch PSW by handshaking with the request line req and the response line ack, and controls the power supply state of the circuit block BLK. Here, the power switch PSW is turned on by setting the request line req to the 'H' level (time T1), and power is supplied to the circuit block BLK. After the power switch PSW is completely turned on and the power supply to the circuit block BLK is completed, the response line ack becomes the “H” level (time T1B), so that the circuit block BLK can operate outside the power switch control circuit. Notify that the status has been changed. Conversely, by setting the request line req to the “L” level (time T2), the power switch PSW is turned off, and the circuit block BLK is controlled to be in the power-off state. When the power switch PSW is completely turned off and the response line ack is set to the “L” level (time T2B), the fact that the circuit block BLK has shifted to the power shut-off state is notified outside the power switch control circuit.

  In FIG. 8, a signal indicating the on / off state of the power switch is output from the power switch control circuit to the micro I / O through the signal lines cs and cr. In the configuration example of FIG. 11, the signal line c corresponds to those signal lines, and the signal line c is determined sufficiently earlier than the response line ack. For example, the signal line c is at the “H” level before the response line ack becomes the “H” level (time T1A). In addition, the signal line c is at the “L” level before the response line ack is at the “L” level (time T2B). Thus, the signal line c is determined sufficiently earlier than the response line ack. After the control of the power switch PSW, in the state where signals can be input / output to / from the circuit block BLK, if the micro I / O is not operable, communication between the circuit blocks will malfunction. It is desirable to control the micro I / O to be operable by the signal c before the response line ack is fixed to the “H” level.

  For simplicity, the circuit block is described as being connected to the ground via a power switch. However, if the DC power consumption due to leakage current does not matter, the power switch There is no need to shut off the power supply. For example, an I / O buffer that operates at a high operating voltage and includes a transistor having a thick gate insulating film corresponds to this example. Further, in some cases, the circuit is composed of transistors having a high threshold voltage, and DC power consumption may not be a problem. In that case, it is not necessary to connect to the ground via the power switch. Whether or not to use the power switch is determined according to the configuration of the MOS transistor constituting the circuit block and the characteristics of the circuit constituting the circuit block.

  In addition, when a circuit block is connected to the ground via a power switch, it is possible to suppress noise generated from a certain circuit block from propagating to another circuit block via the ground. Noise propagation through the ground wire is attenuated through the power switch. This is because the power switch corresponds to a resistor, and a low-pass filter is formed by the resistor, the parasitic capacitance of each circuit block, and the parasitic capacitance of the ground line. For example, consider a case where the circuit block BLKA is a digital circuit that operates at high speed, and the circuit block BLKB is an analog circuit such as a high-precision A / D converter. In general, since a power supply voltage lower than that of an analog circuit is applied to a digital circuit, it is appropriate that power supply VDDA <power supply VDDB. In general, the ground VSSA and the ground VSSB are connected within the chip or outside the module. In this case, since the power supply VDDA and the power supply VDDB are different from each other in voltage, they are separated outside the module, so that the noise of the digital circuit generated in the power supply VDDA hardly propagates to the power supply VDDB. However, since the ground VSSA and the ground VSSB are connected, if there is no power switch, the noise of the digital circuit is directly propagated to the analog circuit via the ground VSSA and the ground VSSB. However, when the power switch is provided at the ground, the description will be made in accordance with the configuration example of FIG. 8. Noise generated from the digital circuit is attenuated by the power switch PSWA and propagates to the ground VSSA and the ground VSSB. Further, the noise on the ground VSSA and the ground VSSB is also attenuated by the power switch PSWB and propagates to the virtual ground line VSSMB which is a substantial ground line of the analog circuit. In this way, noise coupling between the digital circuit and the analog circuit can be reduced.

<Third Embodiment>
Various connection forms of the substrate terminals (wells) of the MOS transistors constituting the circuit block can be considered. FIG. 12 shows a configuration example in which the substrate terminal vbp of the PMOS transistor MP2 is connected to the power supply VDD, and the substrate terminal vbn of the NMOS transistor MN2 is connected to the ground VSS. By connecting the substrate terminal vbn of the NMOS transistor MN2 to the ground VSS, the potential of the virtual ground line VSSM rises when the power switch PSW is turned off, so that the substrate bias is applied between the source and the substrate of the NMOS transistor MN2. Will be applied. Thereby, the leakage current flowing through the NMOS transistor MN2 due to the substrate bias effect can be reduced. On the other hand, vbn may be connected to the virtual ground line VSSM. In this case, the well potential and the source potential of the NMOS transistor MN2 are equal, which is suitable for high-speed operation of the transistor.

  The configuration example of FIG. 13 is an example in which the substrate voltage control circuit VBC controls the potentials of the substrate terminal vbp of the PMOS transistor MP2 and the substrate terminal vbn of the NMOS transistor MN2 constituting the circuit block. The potentials of vbp and vbn are not particularly limited. In order to operate the circuit block BLK at high speed, a low voltage (VDD or lower voltage) is used for vbp, and a high voltage (VSS or higher voltage) is used for vbn. May be applied. Furthermore, an optimum potential may be applied to the substrate terminals vbp and vbn according to the operation speed required for the circuit block BLK. In particular, if the potential is determined according to the process, temperature, and power supply voltage, process variations and temperature / power supply voltage fluctuations can be compensated.

  Although FIG. 12 and FIG. 13 show configuration examples of the inverter circuit in the circuit block BLK, this is merely shown as a typical example of the CMOS logic circuit, and can be applied to various circuits.

<Fourth embodiment>
A circuit block layout will be described. FIG. 14 shows a layout arrangement example of the circuit block BLK shown in FIG. RUSR is an area where MOS transistors constituting the circuit block BLK are arranged. In the ring-shaped area composed of RPWR1, RPWR2, RPWR3, RPWR4, RPWR5, RPWR6, RPWR7, and RPWR8, the power trunks such as the power line VDD, ground line VSS, and virtual ground line VSSM in FIG. 12 are relatively thick. The power supply ring is formed around the wiring having the wiring width. Thereby, the resistance of the power supply line, the ground line, and the virtual ground line supplied to the MOS transistors constituting the circuit block is reduced.

  The power switch PSW is desirably disposed in the four side regions (RPWR2, RPWR4, RPWR6, RPWR8) of the power ring. In particular, the power switch PSW is preferably arranged in the regions RPWR4 and RPWR8. As shown in FIG. 15, the power supply line VDD105 (M1) and the virtual ground line VSSM105 (M1) for supplying power and ground to the standard cells CELL constituting the circuit block extend in the horizontal direction. Therefore, the influence of the wiring resistance can be reduced by arranging the power switch PSW in the regions RPWR4 and RPWR8. On the other hand, when the power switch PSW is arranged in the regions RPWR2 and RPWR6, the influence of the wiring resistances of the power supply line VDD and the ground line VSS arranged in the regions RPWR4 and RPWR8 increases. Therefore, when the power switch PSW is preferentially disposed in the regions RPWR4 and RPWR8, and it is desired to further reduce the influence of the on-resistance of the power switch PSW, it is desirable to dispose the power switch PSW also in the regions RPWR2 and RPWR6. Further, the power switch control circuit PSC shown in FIG. 12 and the like and the substrate bias control circuit VBC in FIG. 13 can be arranged in the four corner regions (RPWR1, RPWR3, RPWR5, RPWR7) of the power supply ring. As the circuit block becomes larger, the area RUSR becomes larger. Accordingly, the areas RPWR2, RPWR4, RPWR6, and RPWR8 also become larger, and the power switch PSW can be arranged so that the gate width corresponds to the size of the circuit block. . On the other hand, the sizes of the regions RPWR1, RPWR3, RPWR5, and RPWR7 are not affected by the scale of the circuit block. From this point of view, it is desirable to arrange the power switch control circuit PSC and the substrate bias control circuit VBC of FIG. 13 in the four corner regions of the power ring.

  FIG. 15 illustrates a more specific layout of the power supply line VDD, the ground line VSS, and the virtual ground line VSSM for the portion R14 in FIG. VDD100 to VDD110 are power supply lines, VSS101 to VSS103 and VSS107 to VSS113 are ground lines, and VSSM101 to VSSM107 are virtual ground lines. SIG100 shows only one wiring representative of the wiring crossing the power supply ring in the vertical direction, and SIG101 shows only one wiring representative of the wiring crossing the power supply ring in the horizontal direction. The symbols M1 to M4 described in parentheses after each symbol in FIG. 15 indicate the names of the wiring layers used for installing the wiring. When a plurality of descriptions are described, it indicates that the wiring is performed by the plurality of wiring layers. M4 is an upper wiring layer as viewed from the semiconductor substrate than M3, M3 is higher than M2, and M2 is higher than M1. In addition, square symbols with X marks indicate vias (VIA) for connecting the wiring layers. A portion indicated by RPWR is a power supply ring region, and a portion indicated by RUSR is a region where MOS transistors constituting a circuit block are arranged.

  The power supply ring is composed of VDD101 to VDD103, VSS101 to VSS103, VSSM101 to VSSM103, and VSS111 to VSS113 by wiring layers M2 to M4 that are relatively higher than the semiconductor substrate. Since the wiring layer relatively higher than the semiconductor substrate can have a wider pitch than the lower wiring layer, the wiring layer thickness can be increased, the sheet resistance can be reduced, and a low resistance wiring can be realized. By using such a low-resistance wiring for the power supply ring, the power supply ring can be formed with a low resistance, and so-called voltage drop can be suppressed small.

  In FIG. 15, a vertical power supply trunk line RPWRV that shunts the power supply ring in the vertical direction is formed by VDD 106 and VSSM 106. Further, a lateral power supply main line RPWRH that shunts the power supply ring in the lateral direction is formed by VDD 107, VSS 107, and VSSM 107. As a result, the resistance of the power supply ring can be further reduced. Here, the horizontal arrangement interval of the vertical power supply trunk line RPWRV and the vertical arrangement interval of the horizontal power supply trunk line RPWRH are not particularly limited, but a relatively lower M2 wiring layer is used for the vertical power supply trunk line RPWRV. Therefore, if too many vertical power supply main lines RPWRV are arranged, the number of channels for signal line wiring of the MOS transistors constituting the circuit block is reduced. Therefore, for example, it is appropriate to arrange them at intervals of about 100 μm. On the other hand, since the M4 wiring layer which is a relatively upper layer is used for the lateral power supply main line RPWRH, the number of channels for the signal line wiring is rarely reduced. Therefore, a large number of horizontal power supply trunks RPWRH can be arranged.

  The power supply RCELL from the power ring to the MOS transistors constituting the circuit block is performed by VDD 105 and VSSM 105 using the M1 wiring layer. When a circuit is configured by arranging many standard cells CELL100, RCELLs are arranged in the vertical direction at intervals of the standard cells so that power is supplied to all the cells. Note that the channels for wiring the signal lines of the MOS transistors constituting the circuit block mainly use the wiring layers M1 to M3. For the same reason, an M4 wiring layer is used for the power supply line and the grounding line in the four corner regions of the power supply ring, and no lower layer wiring is used. When the power switch control circuit PSC and the substrate bias control circuit VBC are provided, the circuit is configured using a sufficient number of wiring layers M1 to M3. When these circuits are not provided, these wiring layers can be used for power supply lines and ground lines.

  Power supply and ground are supplied from the outside of the power supply ring to the power supply ring by VDD109, VDD110, VSS109, and VSS110. Since the M4 wiring layer and M1 wiring layer are used respectively, the M2 wiring layer and the M3 wiring layer should be used for the signal line wiring between the circuit block and the micro I / O as shown by SIG100 and SIG101. Can do.

  For simplicity, only one wiring VDD108 for electrically connecting VDD100 and VDD103 is shown in the figure, but it is actually appropriate to arrange a large number of wirings at a certain interval and connect them to a low resistance. Further, although wiring for directly electrically connecting VDD100 and VDD101 in the vertical direction as in VDD108 is not shown in the figure, it is desirable to arrange them in the same manner as VDD108 using an M2 wiring layer. For simplicity, only one wiring VSS108 for electrically connecting VSS103 and VSS113 is shown, but in practice it is appropriate to arrange a large number of wirings at a certain interval and connect them to a low resistance. is there. Further, although wiring for directly electrically connecting VSS 101 and VSS 111 in the vertical direction as in VSS 108 is not shown, it is desirable to arrange them in the same manner as VSS 108 using an M3 wiring layer.

  With the above layout, it is possible to efficiently supply power to the standard cell CELL100 by using the wiring layer efficiently. FIG. 15 shows a configuration example in which there are four wiring layers. However, if there are more wiring layers, the power supply ring can be further reduced in resistance by using the wiring layers in the configuration diagram of FIG. Can be configured. Although the specific usage method of the wiring layer is not limited, the uppermost wiring layer (M4 in FIG. 15) and the lowermost wiring layer (M1 in FIG. 15) are used to connect the power supply ring from the outside to the power supply ring. It is appropriate to supply power and ground. Thereby, many wiring layers can be used efficiently for signal line wiring between the circuit block and the micro I / O. Further, the lateral power supply main line RPWRH is preferably realized by using the uppermost wiring layer (M4 in FIG. 15). This is because a large number of channels for wiring the signal lines of the MOS transistors constituting the circuit block can be obtained.

<Fifth embodiment>
FIG. 16 shows an example of a chip cross-sectional view of the present invention. PSUB100 is a P-type substrate, NW100 and NW110 are N-type wells, PW100 and PW110 are P-type wells, and NISO100 and NISO110 are impurity layers generated deeper than NW100 and NW110. Deep N type well. P100 and P101 are P-type diffusion layers, and together with the gate electrode G100 and the gate insulating film T100, constitute a PMOS transistor MP100. P110 and P111 are also P-type diffusion layers, and constitute a PMOS transistor MP110 together with the gate electrode G110 and the gate insulating film T110. N100 and N101 are N-type diffusion layers, and together with the gate electrode G101 and the gate insulating film T101, constitute an NMOS transistor MN100. N110 and N111 are also N-type diffusion layers, and constitute the NMOS transistor MN110 together with the gate electrode G111 and the gate insulating film T111. N102 is an N-type diffusion layer and is a substrate terminal of the PMOS transistor PMOS100 for supplying a potential to the N-type well NW100. P102 is a P-type diffusion layer and is a substrate terminal of the NMOS transistor NMOS100 for supplying a potential to the P-type well PW100. N112 is an N-type diffusion layer and is a substrate terminal of the PMOS transistor PMOS110 for supplying a potential to the N-type well NW110. P112 is a P-type diffusion layer and is a substrate terminal of the NMOS transistor NMOS110 for supplying a potential to the P-type well PW110. S100 is a P-type diffusion layer, and supplies a potential to the PSUB 100 from here.

  By using such a triple well structure, the power supply potential and the ground potential of each circuit block can be set independently. For example, the circuit block BLKA in the configuration example of FIG. 4 can be configured as the MOS transistors MP100 and MN100 on the deep N type well NISO100, and the circuit block BLKB can be configured as the MOS transistors MP110 and MN110 on the deep N type well NISO110. Can be configured. Since the substrate potential of the MOS transistor can be set independently in each circuit block, the configuration example of FIG. 13R> 3 can be realized.

  FIG. 17 shows a layout example of the configuration example of FIG. Here, for the sake of simplicity, only the layout of the deep N-type well of FIG. 16 is shown. NISOBLKA is deep N type well of circuit block BLKA, NISOBLKB is deep N type well of circuit block BLKB, NISOMIOA1 to NISOMIOA3 are deep N type wells of micro I / O pre-stage circuit MIOA, and NISOMIOB1 to NISOMIOB3 are micro I / O post stage circuits MIOB Shows a deep N-type well. The deep N-type well NISOBLKA has the same potential (VDDA) as the deep N-type wells NISOMIOA1 to NISOMIOA3 and may be connected to each other. Since the deep N type well NISOBLKB has the same potential (VDDB) as the deep N type wells NISOMIOB1 to NISOMIOB3, they may be connected to each other. Further, the P-type diffusion layer S100 of FIG. 16 may be provided between the deep N-type wells NISOMIOA1 to NISOMIOA3 and the deep N-type wells NISOMIOB1 to NISOMIOB3. It is possible to reduce the noise generated in the circuit block BLKA and the circuit block BLKB from interfering with each other.

<Sixth Embodiment>
As one of the circuit block test facilitating methods, FIG. 18 shows a configuration example when a scan function is added to the micro I / O of the present invention. In FIG. 18, BLKA is a circuit block on the transmission side, BLKB is a circuit block on the reception side, and MIOb1 to MIObn each indicate a micro I / O for one bit. LA1 to LAn are input signals to the micro I / O, and LB1 to LBn are output signals from the micro I / O. Here, for simplicity, control signals such as cr, cs, and e as shown in FIG. 8 and power-related connections are omitted. si0 is the input of scan data, and the data shifts in the order of si1, si2, and sin.

  A general flip-flop (FF) scan is used to forcibly set the internal state of the flip-flop from the outside of the chip. Here, the input (LA1 to LAn) to the micro I / O is ignored, and the micro I / O output (LB1 to LBn) is forcibly set by the input data from si0. Although a specific configuration example of the micro I / O is omitted, for example, it can be realized by providing a flip-flop in the micro I / O and forming a shift register with a plurality of micro I / Os. Also, by using this scan path, the values of the inputs (LA1 to LAn) to the micro I / O can be output to sin in the order of LAn to LA1. As described above, by adding the scan function to the micro I / O, the function verification of the circuit block can be easily executed in a short time.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments, and various modifications can be made without departing from the scope of the invention. For example, the specific structure and layout structure of the circuit can take various embodiments.

It is a figure which shows the basic Example of this invention. It is a figure which shows the fundamental Example of this invention different from FIG. It is a figure which shows the basic structural example of this invention containing micro I / O. It is a figure which shows the example of a structure of two circuit blocks which may become a different power supply voltage, and the micro I / O between them. FIG. 3 is a diagram illustrating a configuration example of micro I / O for causing the micro I / O to operate normally in the state of the power shut-off case 1; It is a figure which shows the structural example of micro I / O for making micro I / O operate normally in the state of the power shutdown case 1 and the power shutdown case 2. FIG. FIG. 3 is a diagram illustrating a configuration example of a micro I / O for causing the micro I / O to operate normally in the state of the power shut-off case 1 and the power shut-off case 3. FIG. 3 is a diagram illustrating a configuration example of a micro I / O for causing the micro I / O to operate normally in the state of the power shut-off case 1, the power shut-off case 2, and the power shut-off case 3. It is a figure which shows the further detailed structural example of the micro I / O of FIG. It is a figure which shows the input / output signal relationship in which micro I / O of FIG. 9 is permitted. It is a figure which shows the interface structural example of a power switch control circuit. It is a figure which shows the example of a connection of the board | substrate terminal of the MOS transistor which comprises the circuit block. It is a figure which shows the example of a connection of the board | substrate terminal of the MOS transistor which comprises the circuit block different from FIG. It is a figure which shows the layout example (floor plan example) of a circuit block. It is a figure which shows the example of a power supply net | network of a circuit block. It is a figure which shows sectional drawing of a circuit block and micro I / O. It is a figure which shows the example of a layout (example of a floor plan) of a deep N type well of a circuit block and micro I / O. It is a figure which shows the example of a basic composition of this invention containing the micro I / O which added the scanning function. It is a figure which shows the structural example of a level conversion circuit.

Explanation of symbols

BLK1, BLK2, BLKA, BLKB, BLK …… Circuit block
MIO1, MIO2, MIO3, MIO4, MIO, MIOb1, MIOb2, MIObn …… Micro I / O
IOB1, IOB2, IOB3 …… I / O buffer
MIOB1, MIOB2 …… Mini I / O buffer
CHP1, CHP2, CHP3 …… Chip
MDL1, MDL2 …… Module
L11, L12, L13, L21, L22, L23, L24, L31, L32, L33, L41, L42, L43, LA, LB, d ... Signal line group
VDDA, VDDB, VDD …… Power supply
VSSA, VSSB, VSS …… Ground
MIOA …… Micro I / O pre-stage circuit
MIOB …… Micro I / O latter circuit
d1, d2, e, cr, cs, / d2 …… Signal line
PSCA, PSCB, PSC …… Power switch control circuit
ctla, ctlb: Interface signals for power switch control circuit
PSWA, PSWB, PSW …… Power switch
VSSMA, VSSMB, VSSM …… Virtual ground wire
NAND1 …… NAND circuit
INV1, INV2 …… Inverter circuit
AND1 …… AND circuit
LC1 …… Level conversion circuit
MN1, MN2, MN100 …… NMOS transistors
MP1, MP2, MP100 …… NMOS transistors
req …… Request line
ack …… Response line
vbp …… PMOS transistor substrate terminal
vbn …… NMOS transistor substrate terminal
VBC …… Substrate bias control circuit
RPWR1, RPWR2, RPWR3, RPWR4, RPWR5, RPWR6, RPWR7, RPWR8 ... Area that forms the power ring
RUSR: Area where MOS transistors that make up the circuit block are placed
VDD100, VDD101, VDD102, VDD103, VDD104, VDD105, VDD106, VDD107, VDD108, VDD109, VDD110 …… Power supply line
VSS100, VSS101, VSS102, VSS103, VSS104, VSS105, VSS106, VSS107, VSS108, VSS109, VSS110, VSS111, VSS113 …… Ground line
VSSM100, VSSM101, VSSM102, VSSM103, VSSM104, VSSM105, VSSM106, VSSM107 …… Virtual ground line
SIG100, SIG101 …… Signal line
RPWRV …… Vertical power supply trunk
RPWRH: Horizontal power supply trunk
CELL100 …… Standard cell.

Claims (4)

  A first region having a first side extending in a first direction and a second side extending in a second direction intersecting the first direction, wherein a first MOS transistor forming a circuit block is formed; A second region having a third side extending in one direction and a fourth side extending in the second direction, wherein the first side of the first region and the third side are disposed in contact with each other; A third region having a fifth side extending in the first direction and a sixth side extending in the second direction, the second region of the first region being disposed in contact with the sixth side; A seventh side extending in the first direction and an eighth side extending in the second direction; the seventh side is in contact with the fifth side of the third region; and the eighth side is A fourth region disposed in contact with the fourth side of the second region, and the first to third power supply lines are disposed in the wiring layers of the second to fourth regions. In the wiring layer of the first region, fourth and fifth power supply lines extending in the second direction for supplying the operating voltage of the first MOS transistor are arranged, and the first power supply line, the fourth power supply line, Are electrically connected, the third power supply line and the fifth power supply line are electrically connected, and the second power supply line and the third power supply line are connected via a plurality of second MOS transistors, The semiconductor integrated circuit device, wherein the plurality of second MOS transistors are arranged in the second region.   2. The semiconductor integrated circuit device according to claim 1, wherein the plurality of second MOS transistors are arranged in the third region.   2. The semiconductor integrated circuit device according to claim 1, wherein a control circuit for controlling an on state and an off state of the second MOS transistor is provided in the fourth region.   2. The semiconductor device according to claim 1, wherein the first to third power supply lines extend in the first direction in the second region, bend in the fourth region, and extend in the second direction in the third region. Integrated circuit device.

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