KR100224112B1 - Apparatus and method for reading and writing data in fifo having different imput/output data rate - Google Patents

Abstract

The writing and reading methods of systems with different input / output speeds include setting the overlap counter value with the cell size-(write frequency / read frequency) * cell size at power-on, and the signal indicating that the cell is the first one. Phipo writing step that occurs during the clock and writes data of one cell size to Papi, and Pippo reading step to read data written in Pippo from the time when the number of bytes written out of Pippo becomes the value of the overlap counter. Write and read data in parallel.

Description

FIELD OF METHOD FOR READING AND WRITING DATA IN FIFO HAVING DIFFERENT IMPUT / OUTPUT DATA RATE}

The present invention relates to a method for recording and reproducing data on a blister, and more particularly, to a method for recording and reproducing data by devices having different input / output speeds.

In the case of first in first out memory operation in a subscriber matching device of an asynchronous transfer mode switch, a general operation method of a packet is shown in FIG. 1. Referring to FIG. 1, when it is not half full of the PPO, the data write operation is started as in the case of 1B by a write clock such as 1A, and when 1D and the empty signal are deactivated in PIPO. By the same read clock, data read operation is started as in 1e.

In the same way as above, when the read and write operations are performed at different frequencies, the Popo pool or the amplifier state is generated and abnormal operation is performed. In particular, when the write operation is performed at a low speed and the read operation is performed at the same time, the low speed write operation is overtaken by the high speed read operation at the point A of FIG. 1. In this case, the subscriber matching device of the ATM switch that is operated and transmitted on a cell-by-cell basis may cause data depletion of the packet, which may cause serious malfunction.

A conventional method for preventing this is shown in FIG. Referring to FIG. 2, after the writing of data to the PPO is completed by the low-speed write clock such as 2A, the high-speed read clock such as 2c is supplied to read the data stored in the PPO as 2d. As described above, the conventional method separates the write operation from the read operation to prevent errors in data transmission and processing. However, the conventional operation method of the above-described encapsulation has a problem in that the performance of the subscriber matching device is greatly reduced because the data transmission and processing time are required because the writing and reading are serially performed.

Accordingly, an object of the present invention is to provide a method for speeding up a data transmission time by processing data access operations in parallel in a system for accessing data of PIB at different speeds.

It is another object of the present invention to ensure that high speed read operation time is superimposed on low speed write operation time in parallel in a device that operates PIP at different frequencies so that the low speed write operation is not overtaken by the high speed read operation. It is to provide a way to.

In order to achieve the above object, the present invention provides an access method of writing and reading data in different frequencies, and sets an overlap counter value in bytes of one cell- (write frequency / read frequency) * bytes of one cell. By analyzing the value of the overlap counter it is characterized in that to write and read data in parallel to the covered.

1 is a diagram illustrating an access operation of a general cover

2 is a view for explaining the conventional film operation characteristics

3 is a diagram illustrating a configuration of an apparatus for operating a blister in accordance with an embodiment of the present invention.

4 illustrates properties for operating a blister in accordance with an embodiment of the invention.

Fig. 5 is a flowchart showing an operation of writing data to a packet according to an embodiment of the present invention.

Fig. 6 is a flowchart showing an operation of reading data written to a PPO according to an embodiment of the present invention.

An embodiment of the present invention proposes a method of efficiently operating a packet in a device that writes and reads data to and from a different frequency, and assumes a case of performing a low-speed write and a high-speed read operation. The embodiment of the present invention eliminates data exhaustion during such access operation, maximizes transmission and processing efficiency by maximizing the overlap of write and read operation time at the same time, and maximizes transmission and processing efficiency.

3 is a view showing the configuration of a bag operating apparatus according to an embodiment of the present invention, 1 is an input unit 3 and an output unit 4 as a bag operating apparatus. And canopy 2 can be a commercial synchronous canopy. FIG. 4 is a diagram illustrating read and write operation times of the PPO 2 according to an embodiment of the present invention. In FIG. 3, names of the terminals connected to the PPO 2 are shown in Table 1 below.

Signal name function WRCLK write clock WREN write enable PEN programming enable HF half full FRST FIFO reset WSOC write data start of cell WD write data

RDCLK read clock RDEN read enable AE / AF almost empty / almost full flag RSOC read data start of cell RD read data IR input ready

Referring to FIG. 3, the coater 2 (synchronization coater) is programmable to a high water maker and a low water maker. According to an embodiment of the present invention, when the Popo operating device 1 is powered on according to the write and read frequency of the environment to be applied using this function, a count in which the write and read operations of the Popo 2 can overlap as much as possible. The program is used as much as possible, and the counter value at this time programs the value obtained by Equation 1 below.

In Equation 1, Cp is a programming counter value, Cn is the number of bytes in one cell, F1 is a write frequency, and F2 is a read frequency.

FIG. 5 is a flowchart illustrating an operation of writing data to PIPO 2 according to an embodiment of the present invention, and FIG. 6 is a flowchart illustrating an operation of reading data from PIPO 2 according to an embodiment of the present invention.

First, referring to FIG. 5, the data write operation to the PPO 2 is performed. When the PRST is converted from 0 to 1 in step 511, the IR is checked in step 513. If the IR signal is detected to be 1, in step 515, the PEN signal and the WREN signal are set to 0 for one clock period, and the write data WD (0: 6) is output as the value obtained from Equation 1. . Thereafter, in step 517, the PEN signal and the WREN signal are set to one. In step 519, when the HF signal and the AE / AF signal are examined and become 1 at the same time, the recording data WD (0: 8) is output in step 523, the WSOC is generated as 1 during the first one clock, and the WREN is 0. Set to. However, if the HF signal and the AE / AF signal are examined at step 519 and not at the same time, the wait is performed until the FE becomes 1 at step 521. Therefore, in the case of writing data in the PII, the first operation is repeated again after writing as many as one cell while repeating steps 519 to 523.

Next, referring to FIG. 6, the operation of reading data written in the PPO is examined. In step 611, the HF signal indicating that the number of bytes written has become the value of the overlap counter is examined, and if the HF signal is 1, step 613. Reads data from one cell stored in PPO2. In step 615, the HF signal is examined again, and in the case of 1, in step 617, data of one cell stored in the PPO 2 is read again, and in step 619, the HF signal is again examined. In the operation of reading the data stored in the PPO 2 in steps 611 to 621 performed as described above, if the HF signal is 1, the data stored in the P FI 2 is continuously read and output. If the HF signal is 0, the PPO 2 is written. It waits until the HF signal becomes 1 without reading data.

As described above, when the input unit 3 performs a data write and read operation on the PPO 2 according to an embodiment of the present invention, the operation of writing the data to the PPO 2 may be performed by examining the HF signal and the AE / AF signal. When it becomes 1 at the same time, it outputs the data WD (0: 8) to be recorded, generates WSOC as 1 during the first clock and sets WREN to 0 to control the data to be saved. As described above, the data recording operation is repeated by repeating the above operation after writing the data in the PII 2 by one cell size. The above process is repeatedly performed. Therefore, in the case of operating the Popo 2 using different frequencies, data is written to the Popo 2 so that the read operation does not overwrite the write operation.

Then, the output unit 4 checks the AE / AF signal and reads one byte of data through the read data RD (0: 7) and the RSOC bit when it changes to 0 to check whether the RSOC is one. At this time, if the RSOC is 1, the remaining data of one cell is read. Otherwise, the read data byte is discarded and 1 byte of data and RSOC are read again and the above operation is repeated. After reading data of one cell as described above, the AE / AF is checked again, and if the AE / AF is 1, the test operation is repeated until 0, and if the value is 0, the first operation is repeated. Therefore, in the case of operating the Popo 2 using different frequencies, the read operation of the data written in the Popo 2 is controlled so that the write operation does not overwrite the read operation.

Therefore, in the case of operating the Pico 2 using different frequencies as described above, the data is written to the Ppo 2 so that the read operation does not overwrite the write operation, and the write operation is written on the Ppo 2 so that the write operation does not overtake the read operation. Controls reading of binary data. For this purpose, the read and write time can be optimally superimposed when performing the write and read operations of the PIPO 2 to perform the read and write operations of the PIPO 2 in parallel, thereby optimizing the data transmission and processing time.

FIG. 4 is a diagram illustrating a write and read operation time of a PPO 2 in a PIP operation apparatus in which an input / output enables efficient operation at different operating frequencies according to an embodiment of the present invention. In FIG. 4, if the input frequency is 19.44 MHz and the output frequency is 33 MHz, and the size of one cell is 53 bytes, when the transmission efficiency is calculated by Equation 1, 53- (19.4 / 33) * 53 = 32 do. Therefore, the transmission efficiency of (32/53) * 100 = 54% is increased.

As described above, in the case of designing the hardware by using Pappo in an environment where the operating frequency of the input and the output are different, in particular, the amplification of data that may occur between the low speed Ppo writing and the fast Ppo reading operation is eliminated, and The overlap between the write and read operation times can be maximized to optimize parallel transfer efficiency. Particularly, in case of applying the method of operating a packet according to an embodiment of the present invention, a subscriber matching device of an asynchronous transmission mode switch can minimize subscriber cell delay.

Claims (2)

In the writing and reading methods of systems having different input / output speeds, Setting an overlap counter value with the cell size-(write frequency / read frequency) * cell size at power on; A write writing step of generating a signal indicating that the cell is the first one clock and writing data of one cell size to the drawing; A reading step of reading data written in the drawing, from the time when the number of bytes written in one cell written in the drawing becomes the value of the overlapping counter, Write and read control method of the capo characterized in that the writing and reading of the data in parallel to the capo. The method of claim 1, wherein the reading of the encapsulation step comprises: If the data of one byte is a signal indicating that the first byte is the start of the cell, the remaining data is read; otherwise, the read and write control method is characterized in that the discarding of the read data is repeated. .

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