JP2000010951A - Asynchronous data reader, asynchronous data reading method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read stable asynchronous data. SOLUTION: When a multiprocessor part 1 executes write access, a write control signal generation part 2 generates a write control signal and it is supplied to a latch stop signal generation part 3. The latch stop signal generation part 3 generates a latch stop signal when the write control signal is supplied and supplies it to a latch clock generation part 4. When the latch clock generation part 4 receives the latch stop signal, it stops a latch clock. When the micro processor part 1 executes read access, a read control signal generation part 5 supplies a read control signal to a latch part 6 and asynchronous data latched by the latch part 6 is read.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an asynchronous data reading device, an asynchronous data reading method, and a recording medium, and more particularly to an asynchronous data reading device, an asynchronous data reading method, and a recording device capable of stably reading asynchronous data. Regarding the medium.

[0002]

2. Description of the Related Art Conventionally, in a read circuit for reading asynchronous input data, the read data does not change while the multiprocessor is reading the asynchronous data.

[0003]

However, in the above asynchronous input data read circuit, if the time at which the multiprocessor starts reading asynchronous data and the time at which the asynchronous data changes point overlap, uncertainty may occur. There is a problem that data may be read.

[0004] The present invention has been made in view of such a situation, and is to enable stable asynchronous data to be read.

[0005]

According to a first aspect of the present invention, there is provided an asynchronous data readout device for generating a clock synchronized with the asynchronous data, and latching the asynchronous data in synchronization with the clock generated by the generator. Latch means, a stop means for stopping a clock generated by the generation means, and a reading means for reading out asynchronous data latched by the latch means when the clock is stopped. 3. An asynchronous data reading device according to claim 2, wherein said instruction means instructs generation of a clock synchronized with said asynchronous data, and said generation means generates a clock synchronized with said asynchronous data when said instruction means instructs generation of said clock. And latch means for latching asynchronous data in synchronization with a clock generated by the generating means, and reading means for reading out the asynchronous data from the latch means when the asynchronous data is latched by the latch means. I do. The stopping means may instruct the clock generating means to stop the clock when reading the asynchronous data. Further, the stopping means can instruct the clock generating means to generate a clock when reading out asynchronous data. 6. The asynchronous data reading method according to claim 5, wherein the generating step generates a clock synchronized with the asynchronous data, the latching step latches the asynchronous data in synchronization with the clock generated in the generating step, and the generating step generates the clock in the generating step. And a reading step for reading out asynchronous data latched in the latching step when the clock is stopped. 7. The asynchronous data reading method according to claim 6, wherein: an instruction step of instructing generation of a clock synchronized with the asynchronous data; and a generation step of generating a clock synchronized with the asynchronous data when a clock generation is instructed in the instruction step. A latch step of latching asynchronous data in synchronization with a clock generated in the generation step, and a reading step of reading the asynchronous data latched in the latch step when the asynchronous data is latched in the latch step It is characterized by. The recording medium according to claim 7,
A program capable of executing the asynchronous data reading method according to claim 5 or 6 is recorded. In the asynchronous data reading device, the asynchronous data reading method, and the recording medium according to the present invention, when reading the asynchronous data, the clock for latching the asynchronous data is stopped, and the already latched asynchronous data is read. Alternatively, when reading asynchronous data, a clock for latching the asynchronous data is generated, and the asynchronous data latched in synchronization with the clock is read.

[0006]

FIG. 1 is a block diagram showing a configuration example of an embodiment of an asynchronous data reading device according to the present invention. As shown in FIG. 1, the multiprocessor unit 1 performs a write access and a read access. The write control signal generator 2 generates a write control signal based on a control signal supplied from the multiprocessor 1.

When the write control signal is supplied from the write control signal generator 2, the latch stop signal generator 3
A latch clock stop signal for instructing to stop a latch clock generated by a latch clock generation unit 4 described later is generated and supplied to the latch clock generation unit 4. The latch clock generation unit 4 outputs an asynchronous clock which is normally synchronized with the asynchronous input data as a latch clock, and stops the latch clock when the latch clock stop signal is supplied from the latch clock stop signal generation unit 3. Has been made.

The read control signal generator 5 generates a read control signal in accordance with the control signal supplied from the multiprocessor 1, and supplies the read control signal to the latch 6. The latch unit 6 latches asynchronous input data in synchronization with the latch clock supplied from the latch clock generation unit 4. When a read control signal is supplied from the read control signal generator 5,
The latched asynchronous input data is supplied to the multiprocessor unit 1 as read data.

Next, the operation of the embodiment shown in FIG. 1 will be described. If you want to read asynchronous input data,
First, the multiprocessor unit 1 performs a write access meaning "latch asynchronous data because we want to read data now." This write access is recognized by the write control signal generator 2, and a write control signal is generated.

The write control signal generated by the write control signal generator 2 is supplied to a latch stop signal generator 3. When the write control signal is supplied from the write control signal generator 2, the latch stop signal generator 3 generates a latch clock stop signal for instructing the latch clock generator 4 to stop the latch clock. It is supplied to the generator 4.

The latch clock generation unit 4 stops the latch clock when the latch clock stop signal is supplied from the latch clock stop signal generation unit 3. This allows
The latch unit 6 stops inputting new asynchronous input data, latches data before stopping the latch clock, and completes preparation of data before reading.

Next, a read access is made by the multiprocessor 1 and a read control signal is generated by the read control signal generator 5. This read control signal is supplied to the latch unit 6. When the read control signal is supplied to the latch unit 6, the latch unit 6 supplies the currently latched data to the multiprocessor unit 1 as read data.

As described above, when reading asynchronous data, the input of asynchronous data is stopped, so that stable asynchronous input data can be read.

That is, even when the asynchronous input data changes at the time of reading the asynchronous data, at the start of reading, and during the reading, the read data read from the latch unit 6 does not change, so that the data can be read stably. .
The reason is that asynchronous data is latched by write access before reading.

FIG. 2 is a block diagram showing a configuration example of another embodiment of the asynchronous data reading device of the present invention.

In the embodiment shown in FIG. 2, FIG.
In this embodiment, the latch stop signal generator 3 and the latch clock generator 4 are replaced by a latch pulse generator 34. Other configurations are the same as those in the embodiment shown in FIG.
Here, the description is omitted.

When a write access is made by the multiprocessor 1, the write control signal generator 2 generates a write control signal and supplies it to the latch pulse generator 34. Upon receiving the supply of the write control signal from the write control signal generator 2, the latch pulse generator 34 generates a latch pulse synchronized with the asynchronous clock.

The latch pulse generated by the latch pulse generator 34 is supplied to the latch 6. Latch section 6
Latches asynchronous input data in synchronization with the latch pulse supplied from the latch pulse generator 34. Thereafter, when read access is performed by the multiprocessor unit 1, the read control signal generation unit 5 supplies a read control signal to the latch unit 6. Upon receiving the supply of the read control signal from the read control signal generation unit 5, the latch unit 6 converts the data previously latched in synchronization with the latch pulse into data.
The data is supplied to the multiprocessor 1 as read data.

As described above, according to the above-described embodiment, before the read access, "Since we want to read data from now,
Latch (hold) asynchronous data. Is performed, the data can be stably read at the time of the next read access. That is, as described above, when there is a write access from the multiprocessor unit 1 that means "I want to read data now, latch the asynchronous data.", Instruct the latch unit 6 to latch the asynchronous data. Then, the latch unit 6 latches the asynchronous data.
Next, when there is a read access from the multiprocessor unit 1, under the control of the read control signal generation unit 5, stable data is output via the latch unit 6.

In each of the above embodiments, a multiprocessor is used, but another processor may be used.

[0021]

As described above, according to the asynchronous data reading device, the asynchronous data reading method, and the recording medium of the present invention, when reading asynchronous data, the clock for latching the asynchronous data is stopped, and the data is already latched. The read asynchronous data is read. Alternatively, when asynchronous data is read, a clock for latching the asynchronous data is generated and the asynchronous data latched in synchronization with the clock is read, so that stable asynchronous data can be read.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an embodiment of an asynchronous data reading device according to the present invention.

FIG. 2 is a block diagram showing a configuration example of another embodiment of the asynchronous data reading device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multiprocessor part 2 Write control signal generation part 3 Latch stop signal generation part 4 Latch clock generation part 5 Read control signal generation part 6 Latch part 34 Latch pulse generation part

Claims (7)

[Claims] A generating means for generating a clock synchronized with the asynchronous data; a latching means for latching the asynchronous data in synchronization with the clock generated by the generating means; An asynchronous data reading device, comprising: stopping means for stopping a clock; and reading means for reading out the asynchronous data latched by the latching means when the clock is stopped. 2. Instructing means for instructing generation of a clock synchronized with asynchronous data; generating means for generating the clock synchronized with the asynchronous data when the instruction means instructs generation of the clock; Latch means for latching the asynchronous data in synchronization with the clock generated by the generating means; and reading means for reading the asynchronous data from the latch means when the asynchronous data is latched by the latch means. An asynchronous data reading device characterized by the above-mentioned. 3. The asynchronous data reading device according to claim 1, wherein the stopping unit instructs the generating unit to stop the clock when reading the asynchronous data. 4. The asynchronous data reading device according to claim 2, wherein the stopping unit instructs the generating unit to generate the clock when reading the asynchronous data. 5. A generating step of generating a clock synchronized with asynchronous data; a latching step of latching the asynchronous data in synchronization with the clock generated in the generating step; An asynchronous data reading method, comprising: a stopping step of stopping a clock; and a reading step of reading out the asynchronous data latched in the latching step when the clock is stopped. 6. An instruction step for instructing generation of a clock synchronized with asynchronous data; and a generation step of generating the clock synchronized with the asynchronous data when the generation of the clock is instructed in the instruction step. A latch step of latching the asynchronous data in synchronization with the clock generated in the generation step; and a read step of reading the asynchronous data latched in the latch step when the asynchronous data is latched in the latch step And a method for reading asynchronous data. 7. A recording medium on which a program capable of executing the asynchronous data reading method according to claim 5 is recorded.