CN1223412A

CN1223412A - Semiconductor IC

Info

Publication number: CN1223412A
Application number: CN 98116352
Authority: CN
Inventors: 小原一刚
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1994-01-19
Filing date: 1998-07-22
Publication date: 1999-07-21

Abstract

A semiconductor integrated circuit capable of reducing the power consumption without increasing the delay time of its critical path includes: a first logic gate circuit (X4) driven by the low voltage source; a second logic gate drive circuit (X1, X2, X3) driven by the high voltage source; as well as a plurality of combined circuits, each combined circuit installed on a signal transmission path, wherein the said semiconductor integrated circuit includes a first combined circuit (X or 5) containing the second logic gate circuit (X1), and the forming of the said second logic gate circuit makes the signal transmission delay time of a special signal transmission path of a critical path, equal to or less than the designed upper limit of the delay.

Description

SIC (semiconductor integrated circuit)

The present invention be that 95 on January 8,, application number are 95101330.0 the applying date, denomination of invention divides an application for the application for a patent for invention of " Rogical synthesizing method and SIC (semiconductor integrated circuit) ".

The present invention relates to the improvement of the Rogical synthesizing method of SIC (semiconductor integrated circuit), more particularly, relate to and a kind ofly can reduce the SIC (semiconductor integrated circuit) that power consumption does not increase the time delay of critical path again.

At present, in the design of SIC (semiconductor integrated circuit), function with register transfer layer (being designated hereinafter simply as RTL) is recorded and narrated the SIC (semiconductor integrated circuit) of representing as development object, and record and narrate with this RTL that to carry out logic synthetic, like this, just adopted the order design that generates the SIC (semiconductor integrated circuit) that to develop.

The RTL that Figure 24 has provided prior art records and narrates.Figure 25 has provided and has used the RTL record by the synthetic logical circuit (SIC (semiconductor integrated circuit)) that is generated of logic.

It is clearly to have stipulated a kind of record that data transmit between a plurality of registers in functional layer that the RTL of Figure 24 records and narrates.In the RTL of this figure records and narrates, r1, r2, r3, r4 are register, func1, func2, func3, func4 are the record of the function of combinational circuit between above-mentioned register, and assign statement and always statement are the statements of recording and narrating the annexation of each register and each combinational circuit.

When recording and narrating the combinator circuit by the RTL of Figure 24, by providing the restriction condition of area or speed, with (trade-off) curve of trading off of area and speed decide circuit,

Recording and narrating in the logical circuit shown in Figure 25 that generates by stating RTL, 101,103,105 and 107 is synthetic the trigger circuit after expressing register r1, r2, r3, r4 in above-mentioned RTL records and narrates and having carried out conversion (mapping) with logic, and they are directly corresponding with register r1, r2, r3, r4 in the RTL record that is shown in above-mentioned Figure 24.The 108th, clock buffer.100,102,104 and 106 is corresponding combinational circuits of func1, func2, func3, func4 (combinational logic circuit) in recording and narrating with the RTL of Figure 24.Combinations thereof circuit 100,102,104 and 106 is to have carried out the circuit after the conversion from the function record of the RTL of Figure 24 as a circuit on area and the trade-off of speed curve.

As suppose that frequency of operation is f, and load capacitance is C, and voltage is V, and then the power consumption P of SIC (semiconductor integrated circuit) can represent with following formula:

P=f·C·V ²

So the power consumption that reduces SIC (semiconductor integrated circuit) has the frequency of operation of reduction f, reduces load capacitance C and reduces by three kinds of methods of supply voltage V, and it is best to reduce the effect of power consumption when reducing supply voltage.

But if be provided with supply voltage low, also will increase the time delay that then has the critical path of maximum delay time in a plurality of paths that constitute logical circuit.

Te Kaiping 5-299624 communique discloses a kind of logic gates, and wherein most do not need to drive with low-voltage source with the logic gates of high speed operation, and remaining needs the logic gates of high speed operation to drive with high voltage source.But above-mentioned Japanese patent application is not disclosed in the problem of considering critical path when using low-tension supply and these two kinds of voltage sources of high-voltage power supply.

When from the logic gates of the tick-over type that drives with above-mentioned such low-voltage source when the logic gates of the high speed operation type that drives with high voltage source transmits data, for example the spy to open flat 5-67963 communique disclosed like that, just need configuration level-conversion circuit between these two logic gates so that the output level of the logic gates that drives with low-voltage source is uprised.But, each combinational circuit that is shown in above-mentioned Figure 25 is the circuit that is made of the sort of a plurality of logic gates that for example are shown in Figure 26 or Figure 27, so in the combinational circuit of this figure, if the supposition critical path is the path shown in the thick line among the figure, then when driving this critical path, just must in each figure, go up judgement and configuration level-conversion circuit in Figure 26 in Figure 27 with the represented a plurality of positions of symbol O (number of this position is 8 places, is 12 places) with high voltage source.In the high SIC (semiconductor integrated circuit) of integrated level, the number of combinational circuit is extremely many, and simultaneously, the number of logic gates that constitutes each combinational circuit is also extremely many.Thereby, in the so high SIC (semiconductor integrated circuit) of integrated level, have in the combinational circuit of critical path, need the number of the position of level-conversion circuit will become a lot, and it is also a lot of to have a number of combinational circuit of critical path.So the number of required level-conversion circuit will become a huge numeral in the whole integrated circuit.The result, in the design of the high SIC (semiconductor integrated circuit) of integrated level, though can judge the position that to establish level-conversion circuit and dispose required level-conversion circuit with few combinational circuit, but the allocation position of judging above-mentioned level-conversion circuit in whole SIC (semiconductor integrated circuit) is not only numerous and diverse but also bother, also want long time, so design effort is very complicated.

The object of the present invention is to provide a kind of time delay of critical path, SIC (semiconductor integrated circuit) low in energy consumption of not increasing.

In other words, the present invention attempts to utilize publication number to reduce total power consumption of SIC (semiconductor integrated circuit) for the technology of 5-299624 Japanese patent application, its method is only to utilize high drive to constitute the logic gates of critical path, and does not increase the time delay of critical path.

To achieve these goals, the present invention is conceived to following 2 points.The 1st, as shown in figure 25, because SIC (semiconductor integrated circuit) is made up of a plurality of registers and a plurality of combinational circuits between each register, so, if on register, dispose level-conversion circuit, then need not on each position in a plurality of combinational circuits (promptly driving the position that to carry out level translation under the situation of critical path with high voltage source), to dispose level-conversion circuit one by one, thereby can reduce the allocation position number of level-conversion circuit.The 2nd, as mentioned above, if in register, dispose level-conversion circuit, then transmitting with this level-conversion circuit in the combinational circuit of data, though be necessary to drive this combinational circuit integral body with high voltage source, but in SIC (semiconductor integrated circuit), the number that is present in the logic gate in the critical path accounts for 5% of the logic gate number that constitutes whole integrated circuit, so the shared ratio in the combinational circuit sum of the combined electrical way with critical path is very little, therefore, even drive the increase that the combinational circuit with critical path also can obviously not cause power consumption with high voltage source.

SIC (semiconductor integrated circuit) of the present invention comprises: first logic gates by the low-voltage source driving; One second logic gates by the high voltage source driving; And a plurality of combinational circuits, each combinational circuit is arranged on the signal transmission path, wherein, described SIC (semiconductor integrated circuit) comprises first combinational circuit that comprises second logic gates, and forming described second logic gates, to make certain be that the signal transmission delay time of the special signal transmission path of critical path is equal to or less than the delay higher limit in the design.

Owing to drive all combinational circuits with high voltage source here, be no more than the delay higher limit of allowing in the design so can be suppressed to the time delay of this critical path with critical path.In addition, because the register in the prime that is arranged in the combinational circuit with critical path disposes a level-conversion circuit, so compare with the situation that only drives critical path with high voltage source, can reduce the number of necessary level-conversion circuit, thereby make the design of SIC (semiconductor integrated circuit) become extremely easy.And even drive all combinational circuits with critical path with high voltage source, because from combinational circuit all, the number with combinational circuit of this critical path extremely lacks, so can suppress the increase of power consumption seldom.On the other hand, because drive a large amount of combinational circuit in no crucial path, so power consumption reduces significantly with low-voltage source.The result can seek the low power consumption of whole SIC (semiconductor integrated circuit).

The contrast accompanying drawing is read following detailed description, and above-mentioned purpose of the present invention and new feature will be more readily apparent from.

Accompanying drawing has provided desirable embodiment of the present invention.

Fig. 1 is the whole summary pie graph of image processing system.

Fig. 2 is the whole summary pie graph of semi-conductor chip.

Fig. 3 has provided a plurality of registers of SIC (semiconductor integrated circuit) and the annexation of a plurality of combinational circuits in the embodiments of the invention.

Fig. 4 is the structural drawing that does not have the trigger circuit of level-conversion circuit.

Fig. 5 is the structural drawing that the trigger circuit of level-conversion circuit are arranged.

Fig. 6 (a) shows the concrete structure of level-conversion circuit.

Fig. 6 (b) shows the another kind of concrete structure of level-conversion circuit.

Fig. 7 is the structural drawing of the latch cicuit of no level-conversion circuit.

Fig. 8 is the structural drawing that the latch cicuit of level-conversion circuit is arranged.

Fig. 9 shows the whole schematic configuration of logic synthesizer.

Figure 10 has provided hardware and has recorded and narrated language.

Figure 11 shows net list (Net List).

Figure 12 has provided schematic circuit diagram.

Figure 13 has provided the Rogical synthesizing method of SIC (semiconductor integrated circuit).

Figure 14 shows the another kind of Rogical synthesizing method of SIC (semiconductor integrated circuit).

Figure 15 shows the variation of the logic synthetic method of Figure 13.

Figure 16 shows the variation of the another kind of logic synthetic method of Figure 14.

Figure 17 (a) is the key diagram that combinational circuit is transformed to the 2nd combinational circuit in the 1st operation.

Figure 17 (b) is the key diagram that the 1st combinational circuit is transformed to again the 2nd combinational circuit in the 2nd operation.

Figure 17 (c) is for resulting from the key diagram that the 1st combinational circuit is transformed to again the 2nd combinational circuit to the conversion again of the 2nd combinational circuit in the 2nd operation.

Figure 17 (d) is the key diagram that register is transformed to the trigger circuit with level-conversion circuit.

Figure 18 shows another kind of SIC (semiconductor integrated circuit) leaved for development.

Figure 19 is the structural drawing of the scanning trigger circuit of no level-conversion circuit.

Figure 20 is the structural drawing that the scanning trigger circuit of level-conversion circuit are arranged.

Figure 21 is the structural drawing of the another kind scanning trigger circuit of no level-conversion circuit.

Figure 22 is the structural drawing that the another kind scanning trigger circuit of level-conversion circuit are arranged.

Figure 23 (a) shows the signal transmission delay of SIC (semiconductor integrated circuit) in the example of prior art and has the distribution of number of the combinational circuit of this delay.

Figure 23 (b) shows the signal transmission delay of SIC (semiconductor integrated circuit) in the embodiments of the invention and the distribution of the number of the combinational circuit with this delay.

Figure 24 shows the record of register transfer layer.

Figure 25 shows the logical circuit of the SIC (semiconductor integrated circuit) of prior art.

The allocation position of level-conversion circuit when Figure 26 shows in SIC (semiconductor integrated circuit) arbitrarily and only to drive critical path with high voltage source.

Figure 27 shows the allocation position that only drives level-conversion circuit when advising critical path at another kind arbitrarily in the SIC (semiconductor integrated circuit) with high voltage source.

Below, according to accompanying drawing relevant each most preferred embodiment of the present invention is described.

Fig. 1 shows the one-piece construction of the image processing apparatus A with SIC (semiconductor integrated circuit) of the present invention.In the figure, 10 for will carry out the A/D converter of mould/transformation of variables from the signal of outside, and 11 is general DRAM.The 12nd, SIC (semiconductor integrated circuit) of the present invention, the 1st SIC (semiconductor integrated circuit) carried out Flame Image Process from above-mentioned DRAM11 taking-up data or when making it to store data.The 13rd, control the general microprocessor of controlling of above-mentioned the 1st SIC (semiconductor integrated circuit) 12.14 for from above-mentioned the 1st SIC (semiconductor integrated circuit) 12 received signals and then carry out the 2nd SIC (semiconductor integrated circuit) of Flame Image Process.

In addition, the 15th, be configured in the high voltage source of outside for example 3V.The 16th, similarly be configured in the low-voltage source of outside for example 2V.Image processing apparatus A among the figure has and is connected to the high pressure wiring 17 that aforementioned high voltage source 15 gets on and is connected to the low voltage wiring 18 that above-mentioned low-voltage source 16 gets on.For trying to achieve the low power consumption of image processing apparatus A, low-voltage source 16 is as the voltage source of the 1st and the 2nd SIC (semiconductor integrated circuit) 12,14 that is used to carry out Flame Image Process, and the low-voltage of low voltage wiring 18 is only supplied with the 1st and the 2nd SIC (semiconductor integrated circuit) 12,14.On the other hand, the high voltage of high pressure wiring 17 is supplied with other

universal circuit

10,11,13.Interface voltage between each circuit 10-14 is necessary for high voltage, so the high voltage of high pressure wiring 17 is also supplied with two

semiconductor devices

12,14 that are used to carry out Flame Image Process.

Aforementioned low-voltage source 16 also can be that the voltage of high pressure wiring 17 is made it inside low-voltage after the step-down (only reducing the size of its threshold voltage) with internal transistor.It constitutes to have published in for example spy opens flat 4-96369 communique, so its details is omitted.In this case, no longer need to be disposed at outside low-voltage source 16.

Fig. 2 shows the inner structure of the 1st SIC (semiconductor integrated circuit) 12 that is used for aforementioned Flame Image Process.In the figure, 20 is chip, 21 ... for being configured in a plurality of i/o pads of aforementioned chip 20 peripheries.22 for removing aforementioned a plurality of i/o pads 21 ... configuring area outside the internal core part, partly be provided with 5 functional block A-E at above-mentioned internal core.Above-mentioned functions piece A-D is the arithmetic processing circuit that carries out nonidentity operation separately, and functional block E for example is the storage unit part of the low capacity of ROM, RAM etc.

In aforementioned the 1st SIC (semiconductor integrated circuit) 12 that is used for carrying out Flame Image Process, the present invention is all applicable to the functional block A-D beyond the functional block E that partly constitutes with aforementioned storage unit in the aforementioned internal core part 22.

Fig. 3 shows the logical circuitry of any one functional block (for example A) of aforementioned the 1st SIC (semiconductor integrated circuit) 12.

Functional block among the figure (part of SIC (semiconductor integrated circuit)) shows according to the RTL record of aforementioned Figure 24 has carried out the synthetic logical circuit of logic.In the figure, 2,4,6,8 is respectively register r1, the r2 that constitutes the RTL record of aforementioned Figure 24, the trigger circuit of r3, r4.1,3,5,7 is respectively to constitute combinational circuit func1, func2, func3 and func4 that the RTL of aforementioned Figure 24 records and narrates and between each register r1-r4 or the combinational circuit of prime.In Fig. 3, in order to make purposes of simplicity of explanation, the output of each combinational circuit only is input in the secondary trigger circuit, gets on but also signal is sent to other combinational circuit sometimes.

Aforementioned trigger circuit the 2,6, the 8th, from the low-voltage source 16 of the aforementioned 2V 2V system as voltage source, remaining trigger circuit 4 are 2V/3V systems that high voltage source 15 these two power supplys with the low-voltage source 16 of 2V and 3V are voltage source.The trigger circuit 4 of aforementioned 2V/3V system have level-conversion circuit as described later, and the

trigger circuit

2,6,8 of 2V system do not have level-conversion circuit.Moreover, aforementioned

combinational circuit

1,3 and 7 is that the low-voltage source 16 with 2V is the combinational circuit (the 1st combinational circuit) of the 2V system of voltage source, remaining combinational circuit 5, owing to require high speed motion, so be that high-voltage power supply 15 with 3V is the combinational circuit (the 2nd combinational circuit) of the 3V system of voltage source.

Also have, the 9th, be the clock buffer (circuit of clock is provided) of the 2V system of voltage source with the low-voltage source 16 of 2V, it forward 4

trigger circuit

2,4,6,8 clock is provided.

There is not the formation of the

trigger circuit

2,6,8 of level-conversion circuit to be shown in Fig. 4 in the aforementioned 2V system.In the figure, the 30th, accept the main latch of external signal D, the 31st, be serially connected with the subordinate latch of two complementary signals of above-mentioned main latch 30 output one sides and output.By main latch 30 that is connected in series and subordinate latch 31 composition data working storages 36.The 32nd, be connected in the output buffer that aforementioned subordinate latch is exported a side.The 33rd, be connected in the output buffer that aforementioned subordinate latch is exported a side.The 33rd, use the internal clocking that produces complementary internal clocking CL, NCK from the clock CLK of outside input to produce circuit (clock supply circuit), these circuit 30-33 is that the low-voltage source 11 with 2V is the 2V system of voltage source.

The formation of trigger circuit 4 with level-conversion circuit of aforementioned 2V/3V system is shown in Fig. 5.These trigger circuit 4 possess has the trigger circuit of structure and the 2V system that is shown in Fig. 42 main latch 30 identical, that be connected in series and subordinate latch 31 and internal clocking to produce circuit 33, and also having simultaneously with the high voltage source 15 of 3V is the output buffer 34 and the level-conversion circuit 35 between aforementioned subordinate latch 31 and aforementioned output buffer 34 of voltage source.Above-mentioned level-conversion circuit 35 is 2V/3V systems.Though the potential difference (PD) between the complementary signal of the subordinate latch 31 of 2V system is low-voltage (2V), having this low voltage signal of input and it is transformed into potential difference (PD) between complementary signal is the function that the high voltage signal of high voltage (3V) is exported.

The concrete formation of aforementioned level-conversion circuit 35 is shown in Fig. 6 (a) and (b).In the level-conversion circuit 35 of Fig. 6 (a), 40 and 41 is pmos type transistors, 42 and 43 is nmos type transistors, the PMOS transistor 40 of a side and the nmos pass transistor of a side 42 serial connections, and nmos pass transistor 43 serial connections of the PMOS transistor 41 of opposite side and opposite side.These two groups of sequential circuits are configured in respectively between the high voltage source 15 and ground of 3V.The grid of the pmos type transistor 40 of an aforementioned side is linked in the drain electrode of nmos type transistor 43 of non-serial connection one side, and the grid of the pmos type transistor 41 of opposite side is connected to the drain electrode of nmos pass transistor 42.Complementary output is taken out from the drain electrode of each nmos pass transistor 42,43.When adopting above-mentioned formation, pmos type transistor 40 and nmos type transistor 42, pmos type transistor 41 and nmos type transistor 43 play a part phase inverter respectively.In other words, when give with the complementary output of the subordinate latch 31 of Fig. 5 the grid of the nmos type transistor 43 of a side be provided with the low-voltage of 2V, when being provided with 0V for the grid of the nmos type transistor 42 of opposite side simultaneously, then when nmos type transistor 43 was opened, nmos type transistor 42 turn-offed.Accompany therewith, the pmos type transistor 41 of opposite side turn-offs when pmos type transistor 40 is opened, so, the drain electrode of one side nmos type transistor 42 is connected on the high voltage source 15 of 3V, the grounded drain of the nmos type transistor 43 of opposite side simultaneously, just obtained the complementary output of the high potential difference of 3V.In the formation of Fig. 6 (a), can be transformed to the complementary output of the subordinate latch 31 of Fig. 5 from the low voltage level of 2V the high voltage of 3V, do not flow to the low-voltage source 16 of 2V and do not have punchthrough current from the high voltage source 15 of 3V, and flow to 0V (ground connection) from the high voltage source 15 of 3V.

Fig. 6 (b) shown with the level-conversion circuit 35 of aforementioned different another kind of concrete structures '.The level-conversion circuit 35 of this figure ' do not dispose two nmos type transistors 42,43 of the level-conversion circuit 35 of earlier figures 6 (a), and replace two CMOS type phase inverters 45,46 of configuration.These two CMOS type phase inverters 45,46 are connected in series by 47,49 and nmos type transistors 48,50 of a pmos type transistor respectively and form.The input terminal of two CMOS type phase inverters 45,46 (two grids of the pmos type that promptly is connected in series and the two transistor of nmos type 47,48 and 49,50) is gone up the complementary output signal that input has the subordinate latch 31 of Fig. 5.(be pmos type transistor 47 and the tie point of nmos type transistor 48 is connected to not the grid of the pmos type transistor 41 that is connected in series with CMOS transistor npn npn 45, the lead-out terminal of the CMOS type phase inverter 46 of opposite side is connected to not the grid of the pmos type transistor 40 that is connected in series with CMOS type phase inverter 46 to the lead-out terminal of the CMOS type phase inverter 45 of one side.The output of two CMOS type phase inverters 45,46 be level-conversion circuit 35 ' complementary output.Adopt above formation, can be transformed to the complementary output of the subordinate latch 31 of Fig. 5 the high voltage of 3V and not have punchthrough current from the low voltage level of 2V and flow to the low-voltage source 16 of 2V, and flow to earthing potential from the high voltage source 15 of 3V from the high voltage source 15 of 3V.Have, the pmos type transistor that constitutes CMOS type phase inverter 45,46 will be suppressed at the punchthrough current that flows to ground connection under the transition state from the high voltage source 15 of 3V again.

Just as recognizing from above explanation, in the SIC (semiconductor integrated circuit) of Fig. 3, the trigger circuit 2 that all have 2V system in

combination circuit

1,3 in its input and output are made of the 2V system of low-voltage; Input end has the trigger circuit 4 of the combinational circuit 3 of 2V system and the combinational circuit 5 that output terminal has the 3V system to be made of low-voltage/high-voltage system (2V/3V system); The trigger circuit 6 that input end has the combinational circuit 5 of 3V system and a combinational circuit 7 that output terminal has the 2V system are made of the 2V system of low-voltage.

In the above description, constitute register r1, r2, r3, r4 with trigger circuit, but also can this trigger circuit and replace with latch cicuit.The concrete structure of described latch cicuit is shown in Fig. 7 and Fig. 8.Fig. 7 shows the latch cicuit 51 of the 2V system of low-voltage.The latch cicuit 51 of Fig. 7 is latch cicuits of no level-conversion circuit, it has input and latchs a signal D with latch (data working storage) 52 that obtains complementary output and the output buffer 53 that is connected in output one side of above-mentioned latch 52, and generate internal clocking NG and the internal clocking that this internal clocking NG outputs to aforementioned latch 52 is produced circuit 53 from external clock G, simultaneously, also external clock G is offered aforementioned latch 52.Above circuit 52-54 is that the low-voltage source 16 with 2V is the 2V system of voltage source.Fig. 8 show the latch cicuit 51 of low-voltage/high-voltage system (2V/3V system) '.The latch cicuit 51 of Fig. 8 ' be the latch cicuit that level-conversion circuit is arranged, the latch cicuit of the 2V system of its structure and aforementioned low-voltage is identical, possess latch 52 that the low-voltage source 16 that has with 2V is a voltage source and internal clocking and produce circuit 54, be the output buffer 5 of voltage source, and between aforementioned latch 52 and aforementioned output buffer 55 and input signal be the level-conversion circuit 56 of high voltage (3V) from low-voltage (2V) level translation with the high voltage source 15 of 3V.The concrete formation of this level-conversion circuit 56 is with to be shown in Fig. 6 (a) or concrete structure (b) the same.

Below, Benq is in the algorithm of the Rogical synthesizing method of the synthetic SIC (semiconductor integrated circuit) that is shown in Fig. 3 of the link information logic of logical block with reference to the process flow diagram of the logic synthesizer of Fig. 9 and Figure 13 and Figure 14.

The whole summary that Fig. 9 shows logic synthesizer 60 constitutes.In the figure, the 61st, read in the unit, the 62nd, translation unit, the 63rd, optimization processing unit, the 64th, element circuit distribution portion, the 65th, timing verification unit, the 66th, circuit diagram generation unit, the 67th, output unit.The net list that the RTL that is shown in aforementioned Figure 24 or Figure 10 records and narrates (hardware record language) and is shown in Figure 11 is imported in the aforementioned unit 61 that reads in, this net list is recorded and narrated with the connection signals layer of logical block based on aforementioned RTL and has been stipulated signal transmission relationship between register clearly, perhaps import with the aforementioned network table graphical the electrical schematic diagram that is shown in Figure 12.Aforementioned translation unit 62 is being transformed into state transition graph, Boolean algebra representation, the specification of storeies such as the type of sequential chart and storer, figure place and number of words from reading in the RTL record of reading in the unit.

Aforementioned optimization processing unit 63 has 63a, 63b, 63c, a 63d and 63e5 part.63a is the state transition graph optimization processing unit that resulting state transition graph is optimized.63b is the state machine generation unit that generates corresponding to the circuit (state machine (state machine)) of optimized state transition diagram.63c is the compiler of sequential chart that the sequential chart that has obtained is compiled.63d is based on the storage synthesis unit of the synthetic storer of specification of resulting storer.63e is the interface unit composite part that is synthesized interface unit by the sequential chart after the compiling and the storer that synthesized according to above-mentioned.In addition, optimization processing unit 63 has logic optimization unit 63f, it is under the situation that is input as the RTL record of reading in unit 61, the link information of the logic unit circuit that has carried out logic optimization and produced optimised according to aforementioned resulting state machine, Boolean algebra representation and synthetic interface unit, and when being sent to the input of reading in the unit and being net list or electrical schematic diagram, optimize the net list be transfused to or the logic of electrical schematic diagram, and produce the link information of the logic of having optimized.

In addition, aforementioned output unit 67 the net list of the logical circuit that above-mentioned Fig. 3 is shown or with this table graphical logical circuit (Schematic) output to the outside.

The present invention is relevant with the unit distribution portion 64 that is shown in above-mentioned Fig. 9.Below, the distribution (unit conversion) that the element circuit that unit distribution portion 64 is thus carried out is described according to the process flow diagram of Figure 13 is handled, promptly according to come the synthetic algorithm that is shown in the SIC (semiconductor integrated circuit) of Fig. 3 of logic by the resulting unit of aforementioned logic optimization unit 63f link information.In addition, in Figure 13, characteristic of the present invention has been described briefly.

In with figure, after the startup, in step S1-S4 (the 1st operation), it is the 1st combinational circuit of voltage source that signal transmission delay is lower than the low-voltage source 16 that the combinational circuit of the delay higher limit in the design synthesizes with 2V.Otherwise it is the 2nd combinational circuit of voltage source that signal transmission delay has been surpassed the high voltage source 15 that the combinational circuit of the delay higher limit in the design synthesizes with 3V.

Aforementioned the 1st operation is carried out as following in the present embodiment.Promptly at first after aforementioned logic optimization unit 63f has read in the link information of unit, in the transmission delay of step S1, each signal transmission path estimation is input to the signal transmission delay on the signal transmission path of data input of subordinate's trigger circuit from the clock of any one trigger circuit with each signal of the trigger circuit of low-voltage (2V) system and combinational circuit.The estimation of sort signal transmission delay will be carried out like this: extract out earlier such as relevant used logic (AND circuit, NOR circuit and NOT circuit etc.) information, the progression of the kind of logic, input number and logic for example, calculate signal transmission delay when this each logical conversion is the unit according to the relevant information of logic therewith and technology of element circuit or the like then, and calculate.Then, judge at step S2 whether the estimation result of signal transmission delay is lower than the higher limit in the design.Be lower than higher limit if find the estimation result, just be transformed to the 1st combinational circuit in the logical block storehouse that is stored in low-voltage (2V) (below be designated as Lib) having a combinational circuit that is located at the logic gates on the signal transmission path at least at step S3.If the estimation result surpasses the higher limit of above-mentioned design, just be transformed to the 2nd combinational circuit that is stored among high voltage (3V) the logical block storehouse Lib having a combinational circuit that is located at a logic gates on the signal transmission path at least at step S4.

Then, carry out following processing at step S5 and S6 (the 2nd operation).Determine whether to exist such form that is provided with in step S5, that is, the output of 2V combinational logic circuit will become the input of 3V combinational circuit.If the result of step is a "Yes", just carry out conversion once more, make being replaced by the combinational circuit of one or more 3V Lib (the 2nd combinational circuit) of combinational circuit (the 1st combinational circuit) of forming aforementioned 2V system for all or part of of one or more 2V logic gates at step S6.Described 2V combinational circuit comprises the logic gates that an output signal is gone to the 3V combinational circuit at least.Wherein, if there be one or more being positioned at that signal is outputed to the logic gates logic gates afterwards that the 3V combinational circuit goes, these one or more logic gates are included later.If the result of step S5 is a "No", just do not need logic gates with 3V logic gates displacement 2V.

Afterwards, decide owing in register, be positioned at the electrical voltage system of its combinational circuit of importing a side and output one side, so will carry out following processing at step S7-S9 (in the 3rd operation) with aforesaid logic is synthetic.Check that promptly whether each register is transformed into current potential the output of high voltage (3V) from the incoming level of low-voltage (2V).When carrying out level translation, this level translation register (trigger circuit or latch cicuit) is transformed to the latch cicuit of the 2V/3V system of the trigger circuit of 2V/3V system of Fig. 5 or Fig. 8 at step S8.When not carrying out level translation, just this register that does not carry out level translation is transformed to the latch cicuit of the 2V system of the trigger circuit of 2V system of Fig. 4 or Fig. 7 at step S9.

Figure 14 shows the variation of the logic synthetic method that is shown in above-mentioned Figure 13.In the Rogical synthesizing method of Figure 13, estimating signal transmission delay in the 1st operation, and according to this estimation result combinational circuit is transformed into the combinational circuit of low-voltage (2V) or the combinational circuit of high voltage (3V).In this variation, be transformed into the combinational circuit (the 1st combinational circuit) of 2V Lib earlier at step S10, then, judge in step 11 whether aforementioned synthetic result is lower than the delay higher limit in the design, and only under the situation that has surpassed the delay higher limit, just carry out conversion once more at step S12, with the 1st combinational circuit with the 2V Lib after aforementioned the synthesizing of the 2nd combinational circuit displacement of 3VLib.Because the 2nd operation of this variation is identical with aforementioned logic synthetic method with the 3rd operation, so save explanation.

Figure 15 shows the variation that the logic that is shown in aforementioned Figure 13 synthetic algorithm has further been specialized.Below, just the different part of Figure 13 illustrates the synthetic algorithm of logic of Figure 15.In the 1st operation, appended step S13.Step S13 is that the estimation result when signal transmission delay surpasses under the situation of higher limit in step S2, extracts a step of the 1st combinational circuit of whole low-voltages (2V) Lib that has surpassed this higher limit in advance out.After the step S13, the 1st combinational circuit of aforementioned extraction is transformed to the 2nd combinational circuit of high voltage (3V) Lib at step S4.In addition, in the 2nd operation, appended step S14.This step is to exist under the situation of combinational circuit of the combinational circuit (the 1st combinational circuit) of 2V system and 3V system in mixing in step S5, in advance the combinational circuit (the 1st combinational circuit) of the 2V system that this mixing the is existed steps of all extracting out.After this step S14,, aforementioned the 1st combinational circuit of having extracted out is transformed into once more the combinational circuit (the 2nd combinational circuit) of high voltage (3V) Lib in step 6.In addition, in the 2nd operation, after abovementioned steps 6 is transformed to the 2nd combinational circuit once more to the 1st combinational circuit, appended the algorithm of returning step 5.Consider and result from the existence that mixes that the conversion to the 3V combinational circuit carried out in abovementioned steps 6 produces 2V combinational circuit and 3V combinational circuit sometimes again, above-mentioned algorithm carries out following process repeatedly: judge whether to exist this mixing in step 5, and when having this mixing, in step S14 and S6, extract the 2nd combinational circuit that exists the 2V combinational circuit of this mixing and the 1st combinational circuit that these have been extracted out is transformed to once again high voltage (3V) Lib once more out.

In addition, Figure 16 shows a kind of variation, and this example is more specific the part of the synthetic algorithm of the logic that is shown in aforementioned Figure 14.This variation is also the same with aforementioned Figure 15, has appended step 15 in the 1st operation, and effect is when signal transmission delay has surpassed higher limit (step S11), extracts the 1st combinational circuit of whole low-voltages (2V) Lib that surpasses this higher limit in advance out.Simultaneously in the 2nd operation, appended step 16, be used for the 1st combinational circuit that when mixing exists 2V combinational circuit and 3V combinational circuit (step S5) extracts the 2V system that whole this mixing exist in advance out, simultaneously, in this 2nd operation, consider sometimes because of (step 6) produces 2V combinational circuit and 3V combinational circuit again mixes situation about existing and appended the algorithm that returns step 5, is used for judging whether to exist this mixing after the processing of step 6 to the conversion once more of the combinational circuit of 3V system.

As previously mentioned, when the signal transmission delay time of finding some the 1st combinational circuit has surpassed the design higher limit, these the 1st combinational circuits are transformed into after the 2nd combinational circuit that draws with hacures among Figure 17 a, the 2V logic gates in these the 1st combinational circuits are transformed into once more the 3V logic gates of the 2nd combinational circuit of representing with hacures among the composition diagram 17b.If this conversion again produces the admixture of a new 2V combinational circuit and 3V combinational circuit, just the 2V logic gates of the 1st combinational circuit is remapped into the 3V logic gates of the 2nd combinational circuit of expressing with hacures among composition Figure 17 C, to eliminate this state.Afterwards, just each trigger circuit current potential when the input of low-voltage (2V) becomes high-tension (3V) output, these trigger circuit that carry out level translation are transformed among Fig. 7 d trigger circuit with the 2V/3V system shown in the hacures.

Figure 18 shows the embodiment that the Rogical synthesizing method of aforementioned Figure 13 is applied to the SIC (semiconductor integrated circuit) of the another kind of structure different with the SIC (semiconductor integrated circuit) of earlier figures 3.

This figure is a kind of SIC (semiconductor integrated circuit) of the trigger circuit that are used for sweep test as register.

Scanning trigger circuit

80,81,82,83 and 84 are scanning trigger circuit of 2V/3V system.Other scanning trigger circuit are scanning trigger circuit of 2V system.

The formation of the scanning trigger circuit of the no level-conversion circuit of 2V system is shown in Figure 19.The scanning trigger circuit of this figure are to have added multi-way switch 90 on the structure of the trigger circuit of the low-voltage that is shown in earlier figures 4 (2V) system.Above-mentioned multi-way switch 90 is that voltage source is also with any one party among two data D of control signal SE selection output and the DT with the low-voltage source 16 of 2V.Be sent to main latch 30 with these multi-way switch 90 selected data.Concerning other formation, on the part identical, be marked with identical symbol and omit explanation with the formation of the trigger circuit that are shown in Fig. 4.

Figure 21 has provided the scanning trigger circuit of the 2V system of another kind of structure.The scanning trigger circuit of the 2V system of this figure have the data input selection circuit 91 on the formation of the trigger circuit shown in earlier figures of being added in 4.Above-mentioned data input selection circuit 91 during with external clock CLK input data D, is forbidden the input of another data DT at main latch, and during the input of main latch 30 forbidden data D, another data DT imports and output to aforementioned main latch 30 with another clock CLKT.In the figure, 92 are internal clocking generation circuit.It is imported above-mentioned two kinds of external clock CLK and CLKT and produces two kinds of internal clocking CKL and NCK, and this internal clocking CK, NCK are outputed to main latch 30 and subordinate latch 31.

Figure 20 shows the scanning trigger circuit of 2V/3V system.These scanning trigger circuit with level-conversion circuit have with main latch 30, subordinate latch 31, the internal clocking of the scanning trigger circuit of the 2V system of Figure 19 and produce the identical circuit of circuit 33 and multi-way switch 90, and the high voltage source that has simultaneously with 3V is the output buffer 95 of voltage source and the level-conversion circuit 96 of 2V/3V system.The level-conversion circuit 96 of above-mentioned 2V/3V system is between subordinate latch 31 and output buffer 95.The concrete formation of the level-conversion circuit 96 of 2V/3V system is identical with preceding Fig. 6 (a) or Fig. 6's (b).

Figure 22 shows the scanning trigger circuit of another 2V/3V system.The scanning trigger circuit of this no level-conversion circuit have with main latch 30, subordinate latch 31, the internal clocking of the scanning trigger circuit of the 2V/3V system of aforementioned Figure 21 and produce the identical circuit of circuit 92 and data input selection circuit 91, and the high voltage source that also has simultaneously with 3V is the output buffer 97 of voltage source and the level-conversion circuit 98 of 2V/3V system.The level-conversion circuit 98 of above-mentioned 2V/3V system is between subordinate latch 31 and output buffer 97.The concrete formation of the level-conversion circuit 98 of 2V/3V system is identical with the formation of earlier figures 6 (a) or Fig. 6 (b).

The following describes the method for the SIC (semiconductor integrated circuit) of the synthetic aforementioned Figure 18 of logic.Suppose that

combinational circuit

86,87,88 has critical path.The algorithm of the Rogical synthesizing method of the aforementioned Figure 13 of foundation, initial conversion stages (the 1st operation) at combinational circuit,

combinational circuit

86,87 and 88 is transformed into the combinational circuit (the 2nd combinational circuit) of 3V Lib, and other combinational circuit is transformed into the combinational circuit (the 1st combinational circuit) of 2V Lib.

Secondly, in the conversion stages again (the 2nd operation) of combinational circuit, combinational circuit 89 is remapped is the combined electrical group of 3V Lib.Secondly, in the conversion stages (the 3rd operation) of register (trigger circuit),

trigger circuit

80,81,82,83 and 84 are transformed into the trigger circuit of 2V/3V system and other trigger circuit are transformed into the trigger circuit of 2V system.

Though the integrated circuit of Figure 18 of aforementioned such generation mixes the logic Lib of the high-voltage system of the logic Lib of the low-voltage system exist 2V and 3V, but the voltage source of each combinational circuit be the low-voltage source 16 of 2V or 3V high voltage source 15 the two one of, so will carry out with the level-conversion circuit in the scanning trigger circuit of 2V/3V system to the high-tension level translation of 3V from the low-voltage of 2V.

The SIC (semiconductor integrated circuit) of aforementioned Figure 18 has 8 scan chain circuits that dot in the drawings, is used for making when scan testing mode signal only not transmit via a plurality of scanning trigger circuit via combinational circuit.For example on the scan chain circuit that is being connected to input Si3, the scanning trigger circuit 81 of 2V/3V system are the same carrying out from the high-tension level translation to 3V of the low-voltage of 2V during with normal mode.The secondary scanning of these scanning trigger circuit 81 triggers, and 99 in circuit carries out from the level translation of high voltage (3V) to low-voltage (2V).Thereby, even use the scanning trigger circuit that are shown in Figure 20 or Figure 22,, also can carry out the low-voltage system of 2V and the high-voltage system of 3V and mix the sweep test of the SIC (semiconductor integrated circuit) of the present invention that exists during the path of combinational circuit (promptly via) scan testing mode inequality in signal transmission path and common path.

In addition, in the above description, the present invention is applied in the internal core 22 of chip 20 the functional block A of formation except that storage unit E that form, but can uses too for other functional block B-D.Self-evident, at a plurality of functional block A-Ds of formation except that storage unit E each other, can use the present invention equally.

Thereby, adopt the Rogical synthesizing method of present embodiment, suppose that the whole combinational circuit with critical path is the high-voltage system of 3V, owing in the register of its prime, dispose level-conversion circuit, so in having the combinational circuit of critical path, when only driving critical path with high voltage source, needn't judge the position that in this has the combinational circuit of critical path, disposes a plurality of level-conversion circuits singly, simultaneously, can reduce the number of necessary level-conversion circuit, make the design of SIC (semiconductor integrated circuit) become extremely easy.And, all use the high voltage source 15 of 3V to drive although have the combinational circuit integral body of critical path, but it is few that the number of the combinational circuit that the number of this combinational circuit with critical path and SIC (semiconductor integrated circuit) are possessed is compared quantity, so can suppress the increase of current sinking.On the other hand, owing to there are not all combinational circuits of critical path all use low-voltage source 16 drivings of 2V, pretend and be SIC (semiconductor integrated circuit) integral body, current sinking can be done not quite, thereby can realize low power consumption.

Below, the SIC (semiconductor integrated circuit) of the prior art of the SIC (semiconductor integrated circuit) of the present embodiment of Fig. 3 and Figure 25 is compared.In the SIC (semiconductor integrated circuit) of the prior art of Figure 25, the signal transmission delay that contains each combinational circuit 100,102,104 and 106 is 6ns as shown in the figure like that, 12ns, 18ns and 8ns, and establish trigger circuit from the clock input time to the data output time 2ns of time delay, then because the maximum-delay of combinational circuit is the 18ns of combinational circuit 104, so the maximum operation frequency of the circuit of Figure 25 will become

1000/(2+18)=50MHz

On the other hand, because the electrical voltage system (3V) of the SIC (semiconductor integrated circuit) of the present embodiment of Fig. 3 is the same time delay with combinational circuit 5 of critical path with prior art, so be all 18ns mutually with prior art time delay.Because the supply voltage that the

combinational circuit

1,3 and 7 in no crucial path uses is from the high voltage reduction of the 3V low-voltage as 2V, thus be accompanied by its time delay logical block time delay increase and become big.Also have, be limited to 20ns on the time delay in the SIC (semiconductor integrated circuit) of Fig. 3 in the supposition design, and will become 1.5 times the time delay of the low-voltage source lower unit of the 2V relative with the high voltage source of 3V.There are not the

combinational circuit

1,3 in crucial path and the time delay (18ns) that 7 maximum delay time will be less than or equal to the combinational circuit 5 with critical path.

The low-voltage source 16 of 2V and high voltage source 15 these two power supplys of 3V are provided in the present invention.Do not have the combinational circuit 3 of critical path and have the combinational circuit 5 of critical path that the signal transmission delay time of a 18ns is respectively arranged, and, from

trigger circuit

2 and 4 receive a clock input the time to be carved into the propagation delay time in the moment of output data be 2ns, so the maximum operation frequency of the SIC (semiconductor integrated circuit) of present embodiment becomes:

1000/(2+18)=50MHz

Even the low-voltage source 16 with 2V drives

combinational circuit

3 and 5, also can obtain the maximum operation frequency identical with the SIC (semiconductor integrated circuit) of prior art.

Figure 23 has provided in the SIC (semiconductor integrated circuit) of the prior art of the SIC (semiconductor integrated circuit) of the present embodiment of Fig. 3 and Fig. 5, delay from the clock input time of trigger circuit to the data input time of secondary trigger circuit is promptly the distribution of the signal transmission delay of adding up the time delay of register and combinational circuit.The delay of SIC (semiconductor integrated circuit) that with figure (a) is the 3V electrical voltage system of prior art distributes, and is that the 2V system of present embodiment and delay that the SIC (semiconductor integrated circuit) that exists is mixed by the 3V system distribute with figure (b).In the SIC (semiconductor integrated circuit) of prior art, when only supply voltage when the high-voltage system of 3V becomes the low-voltage system of 2V, maximum delay time will become 30ns from 20ns, will be above the delay upper limit in the design of critical path delay time.To this, in the SIC (semiconductor integrated circuit) of the present embodiment of Fig. 3, only the combinational circuit that critical path is arranged that surpasses 20ns its time delay is transformed to the high-voltage system of 3V, the combinational circuit in the crucial path of other nothing is the low-voltage system of 2V, so can satisfy the delay higher limit 20ns in the design.The delay that has provided this moment with figure (b) distributes.

Below, compare semiconductor integrated circuit and semiconductor integrated electric of the present invention in prior art Power consumption in the road. The power consumption of supposing the semiconductor integrated circuit of prior art is P, and power supply is 3V's Two power supplys of the low-voltage source of high voltage source and 2V, and all middle critical path institutes of circuit accounting Rate is 10%, the circuits for triggering of 2V/3V of the present invention system are because of with the circuits for triggering of prior art Circuit consists of different and power consumption increase that form is 10%, then semiconductor integrated circuit of the present invention Power consumption be shown below,

[P×(2/3)] ²×0.9+P×1.1×0.1=P×0.51

Power consumption has been subdued 49% more than.

In addition, under these conditions, if supposition shared ratio of critical path in circuit is all is 5 %, then the power consumption of semiconductor integrated circuit of the present invention is shown below,

[P×(2/3)] ²×0.95+P×1.1×0.05=P×0.48

Power consumption has been cut down 52% more than.

Next, compare the SIC (semiconductor integrated circuit) of prior art and the circuit scale of SIC (semiconductor integrated circuit) of the present invention.

If the circuit scale of SIC (semiconductor integrated circuit) of supposition prior art be in S, the SIC (semiconductor integrated circuit) the shared ratio of trigger circuit be 20% and SIC (semiconductor integrated circuit) in the shared ratio of critical path be 10%, and the trigger circuit of establishing 2V/3V of the present invention system different to make the area increment of formation be 10% because of constituting with the circuit of the trigger circuit of prior art, then the circuit scale of SIC (semiconductor integrated circuit) of the present invention will become as shown in the formula like that:

S×0.8+S×0.18+S×1.1×0.02=S×1.002

The increase of circuit scale is not more than 0.2%.

In addition, under these conditions, suppose that critical path shared ratio in entire circuit is 5%, then the circuit scale of SIC (semiconductor integrated circuit) of the present invention is shown below, and will become:

S×0.8+S×0.19+S×1.1×0.01=S×1.001

The increase of circuit scale is not more than 0.1%.

Claims

1. SIC (semiconductor integrated circuit) comprises:

One first logic gates (X4) by the low-voltage source driving;

One second logic gates by the high voltage source driving (X1, X2, X3); And

A plurality of combinational circuits, each combinational circuit are arranged on the signal transmission path,

Wherein, described SIC (semiconductor integrated circuit) comprises first combinational circuit (X or 5) that comprises second logic gates (X1), and forming described second logic gates, to make certain be that the signal transmission delay time of the special signal transmission path of critical path is equal to or less than the delay higher limit in the design.

2. SIC (semiconductor integrated circuit) as claimed in claim 1 comprises that also one comprises first logic gates but do not comprise second combinational circuit (3,7) of second logic gates, and this second combinational circuit satisfies the delay higher limit in the design.

3. SIC (semiconductor integrated circuit) as claimed in claim 1, wherein, the logic gates on the signal transmission path of described first combinational circuit (X) comprise first logic gates (X4) and second logic gates (X1, X2, X3).

4. SIC (semiconductor integrated circuit) as claimed in claim 3, wherein, in first combinational circuit (X), the input end of first logic gates (X4) links to each other with the output terminal of second logic gates (X1).

5. SIC (semiconductor integrated circuit) as claimed in claim 1, wherein, the output terminal of another described second logic gates (X2) is connected to second logic gates (X1) input end in first combinational circuit (X), and the input end of first logic gates (X4) is connected to the output terminal of second logic gates (X1) in first combinational circuit (X).

6. SIC (semiconductor integrated circuit) as claimed in claim 1, wherein, (5c X1) is second logic gates to all logic gates on the signal transmission path of first combinational circuit (5) for 5a, 5b.

7. SIC (semiconductor integrated circuit) as claimed in claim 6, wherein, described second logic gates (5a-5c, X1) in the input end of each second logic gates at least one the signal transmission path of output terminal and first combinational circuit (5) link to each other.

8. SIC (semiconductor integrated circuit) as claimed in claim 1, also comprise a level converter (4), be used for receiving the low pressure output signal of first logic gates of first combinational circuit 3, the level translation of this low-voltage signal is become the level of high-voltage signal, then this high-voltage signal is outputed to second logic gates (5a).

9. SIC (semiconductor integrated circuit) as claimed in claim 8, wherein, level converter (4) is one to have the register of level translation function, it receives and stores the low pressure output signal of first logic gates, the level translation of the low-voltage signal of this storage is become the level of high-voltage signal, then this high-voltage signal is outputed to second logic gates.

10. SIC (semiconductor integrated circuit) as claimed in claim 9, wherein, described register (4) with level translation function comprising: a usefulness low-voltage source is as the data working storage (36) of its voltage source, and a usefulness high voltage source also is transformed into high pressure output signal level transducer (35) to described low pressure output signal according to working storage as its voltage source.