JPS61259360A - Self-strobe signal generating system - Google Patents

Abstract

PURPOSE:To attain transfer of data of lots of kinds through a few tag lines by using the changing state of plural tag signals and a self strobe signal sent from a strobe signal generating section so as to control data transfer to a module. CONSTITUTION:The changing state of a tag signal transferred from a host device through, e.g., through three tag lines TAG0-TAG2 is detected by a changing point detection section 111. That is, the section 111 is driven by clock signals CLKZ, CLKB having inverted phase, the state of the tag signal at that time is recorded respectively, and if the recording state differs, it is discriminated as the change in the tag signal, a detection signal CMP is reset. A strobe signal generating section 113 uses the signal CMP to generate a strobe signal STRB by itself. Thus, lots of kinds of data are transferred without provision of an exclusive strobe signal line and limit in the changing method of the tag signal.

Description

[Detailed Description of the Invention] [Summary] This is a self-strobe signal generation method that detects changing states of multiple tag signals and generates a strobe signal automatically in response to a strobe signal transferred from a host device. The transfer data can be easily captured using a simple signal line.

[Industrial application field]

The present invention relates to a self-strobe signal generation method that self-generates a gate signal for capturing data transferred from a host device through a common bus.

For example, as a method for specifying the type of data that is transferred between a higher-level device and a plurality of input/output devices in a computing system through a common bus, there is a method in which a tag indicating the type of data is attached to the data itself.

The side receiving and receiving the transferred data checks the tag of the data to identify its type and performs the appropriate processing, making it possible to process different types of data even with fewer types of instructions.

However, on the other hand, the processing becomes complicated. The development of a simple processing method based on the tag method is awaited.

[Prior art and problems to be solved by the invention] FIG. 4 shows a system configuration diagram, and FIG. 5 shows a conventional signal output status diagram.

A plurality of modules 1(0) to 1(n) shown in FIG. 4 exchange data with the host device 2 through a common bus a. For example, in order to recognize that the data sent from the host device 2 to the common bus a is the data being transferred to the module 1(i), the change state of the tag signal sent to the tag signal line Recognize by.

Further, the data is taken in while the strobe signal sent from the host device 2 through the strobe signal line C is "on" when the tag signal is in a changing state. This situation is shown in FIG.

The tag signal line shown in Figure 4 consists of multiple signal lines, and it is possible to transfer many tag signals by combining these multiple signal lines. Previously, C was required.

On the other hand, in the conventional method that does not provide a dedicated strobe signal lc, changes in multiple tag signal lines are limited to only one signal line changing at a time. The interface unit (IHi) of the tag recognizes the data, generates a strobe signal, and captures the data, but there is a problem in that it is not possible to transfer many tag signals.

[Means for solving problems]

FIG. 1 shows a principle block diagram of an interface unit according to the present invention.

FIG. 1 shows a changing point detecting section 111 that detects changing states of a plurality of tag lines TAGi by driving them with clock signals CIJA and CLKB having different phases, and a changing point detecting section 111 that detects changing states of a plurality of tag lines TAGi, and a predetermined state is set by a change in the output of the changing point detecting section 111. Flip-flop 112 (hereinafter referred to as F, F112
and a strobe signal generating section 113 that generates a self-strobe signal 5TRB based on the set state outputs of F and F112 and outputs it to a portion (not shown) of module 1(i).

[Effect]

For example, the change point detection unit 111 detects a change state of a tag signal transferred from the host device 2 through a small number of tag lines (for example, three tag lines TAGO to TAGO2).

That is, clock signals CLKA, CLK with opposite phases
B, the state of the tag signal at that time is recorded, and if there is a difference in the recorded state, it is assumed that the tag signal has changed and the detection signal CMP drops.

Using this detection signal CMP, the strobe signal 5TRB is
By self-generating the tag signal, many types of data transfers are possible without providing a dedicated strobe signal line and without placing restrictions on the method of changing the tag signal.

〔Example〕

The gist of the present invention will be specifically explained below with reference to embodiments shown in FIGS. 2 and 3.

FIG. 2 is a block diagram explaining the present invention in detail, and FIG. 3 is a diagram showing the operation of each signal according to the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

Next, the operation of this embodiment will be explained. The embodiment shown in FIG. 2 is based on the strobe signal in the interface units 11(0) to 11(n) that control the interface with the host device 2 in the modules 1(0) to 1(n) shown in FIG. 5TRB
A block diagram for generating is shown.

Further, the strobe signal 5TRB is used as a signal for safely receiving data sent from the host device 2 on the side of the module Hi).

The tag signal TARO-TAG2 shown in FIG. 2 is a control signal sent from the host device 2 to each module 1(0) to 1(n), and the control content is based on three tag signals TA.
Displayed by the combination of RO to TAG2.

Further, the clocks CLKA, CLKB, and CLKI are signals generated inside the module 1(i), and in particular, the clocks CLKA and CLKB are clock signals having opposite phases to each other as shown in FIG.

The tag signals TARO to TAG2 sent from the host device 2 to each module 1(O) to 1(n) are sent out almost simultaneously, but with a maximum variation of T1 due to the influence of the distributed capacitance of each tag line. It arrives at the interface section 11(i).

The register 111a is driven by the clock CLKA and stores the changing state of the tag signal TARO-TAG2, and the register 111b is driven by the clock CLKB and stored. Furthermore,
The contents stored in register 111a and register 111b are compared by comparison circuit 111c, and if there is a difference, a predetermined signal CMP is dropped. Note that if the contents are the same, the signal output will not change.

A difference between the contents stored in the register 111a and the register 111b indicates that there has been a change in the states of the tag signals TARO to TAG2. That is, there is data transmission on the common bus a, and tag signals TARO to TAG are transmitted accordingly.
This indicates that a predetermined control signal has been sent from No. 2.

P and F112 are set by a change in the predetermined signal CMP output from the comparator circuit 111c, and the shift register 113
Start a. When a predetermined period of time has elapsed after the shift register 113a is activated, a predetermined signal is sent to one input terminal of the AND circuit 113c, and thereby the strobe signal 5TRB
becomes “on” and continues for 14 hours, and the inverter 113b
When a predetermined signal is sent to the input terminal side of the switch, the switch is turned off.

F, F112 and the shift register 113a change the output side of the inverter 113b (i.e. from "on" to "off").
It is reset by the following command) and waits for the next operation.

The time until the strobe signal 5TRB turns "on" is 12 hours after the earliest change in the tag signals TARO-TAG2 (tag signal TARO in Fig. 3), and if T2>>Tl. There is.

Furthermore, the minimum period of change of the tag signals TARO to TAG2, that is, the period T3 from the change point of the tag signal TARI to the next change point of the tag signal TARO in FIG. 3, is set so that T3 > T4. shall be.

As described above, the tag signal T transferred from the host device 2
Since the strobe signal 5TRB is generated by itself by detecting the changing state of ARO to TAG2, it is not necessary to provide a dedicated strobe signal line.

[Effects of the Invention] According to the present invention as described above, many types of data can be transferred with a small number of tag lines without providing a dedicated strobe signal line and without placing restrictions on the method of changing the tag signal. It has the effect of saying.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the interface section according to the present invention, Fig. 2 is a block diagram explaining the present invention in detail, Fig. 3 is an operation diagram of each signal according to the present invention, and Fig. 4 is a system configuration diagram. , FIG. 5 shows a conventional signal output situation diagram, respectively. In FIGS. 2 and 4, 1(0) to 1(n) are modules, 11(0) to 11(n) are interface units, and 111
Reference numeral 112 indicates a change point detection unit, and 112 indicates F, F. 113 is a strobe signal generation unit, 111a and 1llb are registers, 111C is a comparison circuit, 113a is a shift register,
113b is an inverter, 113c is an AND circuit, and 2 is a host device.

Claims (1)

[Scope of Claim] In a device in which a host device and a plurality of modules are connected via a common bus, and each of the modules uses the common bus as a common data transfer path, )) includes a tag change point detection section (111) that detects change states of a plurality of tag signals sent from the host device, and a flip signal that is set by a change in the output of the tag change point detection section (111). A flop (112) and a strobe signal generation unit (113) that generates a self-strobe signal based on the output of the flip-flop (112) are provided, and data transfer to the module is based on changing states of the plurality of tag signals; A self-strobe signal generation method characterized in that the self-strobe signal is captured by a self-strobe signal sent from a strobe signal generation section (113).