JPS6020237A - Disk controller - Google Patents

Abstract

PURPOSE:To eliminate a demand for processing to the host system by storing temporarily data in the buffer, and controlling a titled device so that the data is not outputted from the buffer when the data have not been correctly read. CONSTITUTION:The data from the data bus 105 are temporarily stored in FIFO (First-in, First-out) buffers 1 and 2. The signal line 113 informs the disk of the completion of reading each sector; the signal line-114 is read out from the disk, and informs whether the data, which is written in FIFO buffers 1 and 2, are correctly read or not. When the reading of the sectors including data is completed, while referring to the information of these signal lines 113 and 114. When the data are correctly read, the data is outputted from FIFO buffers 1 and 2 when the data are not crrectly read, the data is not outputted from FIFO buffers 1 and 2.

Description

[Detailed description of the invention] The present invention relates to a disk control device.

Conventionally, it has a function of holding information regarding sectors on a disk, controlling the reading operation of data included in the previous 8C sectors based on this information, and checking whether the data has been read correctly for each sector. The disk control system provides the host system with information about the sectors on the disk that are the target of a read operation and, once commands are received, control of the read operation of data on the disk.
When the reading of one sector is completed, it is checked whether the data contained in the sector has been read correctly.

If the data is read correctly, the information regarding the previous 6C sectors is updated, and it is determined whether all the sectors targeted for the read operation initially specified by the host system have been continued, and the sector is read. If all of the sector has been read, the reading operation is terminated, and if all of the sector has not been read, the reading operation of the next sector is started based on the updated information. This operation is then repeated until all sectors targeted by the read operation initially specified by the host system are read.

If the data is not read correctly, the disk control system does not update all the information regarding the sector including the data, interrupts the host system, passes the information to the host system, and stops the read CM production. The host system performs an ite DMA (Di r
ect Memory Access) controller and issued a command to the disk control system to read the data again.

Therefore, when reading data from a disk, if the data is not read correctly, in order to perform the entire data reading operation again, processing must be performed on the host system, the DMA controller is reinstalled, and the data is read. The drawback was that the command needed to be reissued.

The purpose of the present invention is to eliminate all of the above-mentioned drawbacks and to provide a data transfer method that does not require full processing to the host system. A disk control system has a function of controlling reading operation of data included in the sector based on the data and checking whether or not the data has been read correctly for each sector, a buffer for temporarily storing all of the data; There is a signal line that informs you that the reading of the sector containing the data has been completed, a signal line that informs you whether the data has been read correctly, and an information sound on these signal lines to indicate that the reading of the sector containing the data has been completed. and means for outputting the data from the buffer r when the data is correctly read, and means for not outputting the data from the buffer l when the data is not correctly read; can get.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plot of one embodiment of the present invention.

rff In figure 1, l and 2 are ・6, 256 bytes x 8
FIFO with bit '1LkLfc (First I
n First 0ut) buffer, 101.102 lines each FIFO buffer l.

Signal lines 103 and 104 each indicate whether the FIFO buffer 2 is in the write enable state or not.
1” O buffer 1.Fl14' Signal line that informs whether O buffer 2 is in read enable state, 10
5. 106 is an 8-bit wide data bus, 107 is a write signal line for writing data read from the disk into the FIFO buffer, 108 is a write signal line for PI)"0 buffer 1, 109 is a write signal line for FIFO buffer 2, 1101.1 Read signal line for reading data in the FIFO buffer by DMA transfer,
Reference numeral 111 indicates a signal line for pushing out the li' l FO buffer l, reference numeral 112 indicates a read signal line for the FIFO buffer 2, and reference numeral 113 indicates a signal line indicating that reading of each sector on the disk has been completed. Every time it ends, a one-shit pulse will appear. Reference numeral 114 is a signal line that indicates whether or not the data read from the disk and written to the FIFO buffer was read correctly.If the data was not read correctly, a pulse is sent before the reading of the sector containing the data is completed. A signal is output.

3 is I) Flip 70 knob, and uses the f trace of Shin Yumatsu 113 as the clock input. Reference numeral 115 denotes an output signal line of the D clip-flop 3, which outputs a signal at the same level during the reading operation of the same sector, and the level of the signal is inverted every time reading of the sector is completed.

4 is a multiplexer, and the signal +li'J! When the signal on signal line 115 is ``low'', the signal on signal line 107 is
8, and output to the signal line 109 when the 1st signal of the signal line 115 is l high#.

5 is a demultiplexer, and the signal @115 is low
', the signal line 101 is selected, and when the signal on the signal line 115 is "high", the signal line 102g is selected and output.
h”, the signal from the traffic light 110 is output to the signal line 111, and when the signal on the signal line 115 is “low”, the signal from the traffic light 110 is output to the signal line 111.
Output to 2.

7 is a demultiplexer, and the signal on the signal line 115 is 'hi'.
When the signal on the signal line 115 is "low", the signal line 103 is selected, and when the signal on the signal line 115 is "low", the signal line 104 is selected and output.

8 is a multiplexer and the signal on signal line 115 is 'low'
When , the signal on the signal line 114 is output to the signal line 118 , and when the signal on the signal line 115 is higb'o, it is output to the signal line 119 .

Reference numeral 116 is an output signal line of the demultiplexer 5, which informs whether the selected FIFO buffer is in the write enable state. Reference numeral 117 is an output signal line of the demultiplexer 7, which informs whether the selected FIFO buffer is in a read enable state.

118 is the reset signal line of FIFO buffer 1, 119
is a reset signal line of the FIFO buffer 2.

Next, the operation of this embodiment will be explained. FIG. 2 is a timing diagram of the apparatus of the embodiment shown in FIG. 1 when data contained in the third sector after starting reading data on the disk is not correctly read.

In Figure 2, horizontal @T is the time, 'To is the time when reading the sector on the disk started, Tlrt is the time when reading the first sector was finished, and information about the sector read from the disk at this time is Updated. T2
is the time when reading of the second sector is completed, and information regarding the sector read from the disk at this time is updated. T3 is the time when the reading of the third sector is completed, 'T4 is the time when the reading of the second sector is completed, and at this time, 6 information regarding the sector read from the disk is updated. Also, Figure 2 (6) 1
The signal on the signal line 115 in the figure, Φ) is the signal on the signal line 114 in FIG. 1, and L') is the FIFO corresponding to the one in FIG.
The data signal Qt stored in the buffer l shows a timing diagram of the data signal stored in the FIFO buffer 2 in FIG.

(1) From time To to time T1, the FIFOI write enable signal i 101 is selectively output to the write enable signal line 116 of the FIFO buffer group. The signal on the FIFO buffer group data write signal line 107 is output onto the signal line 108 as a data write signal to the FIFO buffer l. data bus 1
The data on 05 is transferred 1f to FIFO buffer 1, but the read enable signal line 11 of the FIFO buffer group
7 and the data read signal line 110 are not involved in the FIFO buffer IIC, so the data in the FIFO buffer 1 yen is not read out.

(2) From time T1 to T2, the read enable signal line 117 of the FIFO buffer group
read enable signal line 1 of FIFO buffer l.
The signal of 03 is selectively output, and the signal of the data read signal line 110 to the FIFO buffer group is the signal of FIFO buffer 1.
Since it is output onto the signal line 111 as a data read signal to the data bus 106, l-#-FIFO
The data stored in 1 will be output. On the other hand, data Fi≠=≠FIFO2 on the data bus 105 is written.

Similarly below, VC-P#-FIF01 and ≠-F I FO
z is alternately selected for data input/output, and -F
Data is never input/output to/from the IFO buffer at the same time.

(3) Time T, c, n'jJt 'J'3i −
c NobarniP I F(') 11? T f”, Kikomi [
Also, the data is better than the disk :I・”)dT
jlr, :/+, the pulse signal on signal line 114 is outputted by multiplexer 8 onto signal line 118 and the FIFOI is reset. Therefore, from time T3 to time T4, FiF
The signal on the read enable signal line 117 of the O buffer group is not activated, and data that is not correctly read from the disk is not transferred to the host system as an output of the disk control system.

Also, since the information regarding the sector read from the disk at time T3 is not updated, the disk control system restarts reading data on the disk p'ft from time T3 to time T4, and then starts reading data from the third sector p'ft. All data reading operations are performed, and the read data is temporarily stored in the PIFO buffer 2.

If the data is read correctly, at time T4, the disk control system updates the information regarding the sector read from the disk, and performs the sector read operation after time T4.

According to the present invention, when a conventional disk control system reads data on a disk and the data is not read correctly, the read operation is stopped and the DMA controller is reconfigured for the host system. However, in the present invention, when data on the disk is read, if the data is not read correctly, a request is made to the host system to reissue the command to read the data. without requesting processing.
It becomes possible to continue the data reading operation. As a result, the performance of the disk control system can be improved.

In addition, in the license fee shown in Figure 1, the data buffer is temporarily stored in two FIFO buffers, and the buffer company has a fixed input/output order of data and has enough capacity to store all the data contained in one sector. Any buffer is fine.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 (f)
~σ) is the timing diagram. 1.2...FIFO buffer, 3...
1) Norig 70 tube, 4,6.8...Multiplexer, 5,7...Demultiplexer, 101,1
02,116...Write enable signal line,
103,104.117... Read enable signal line, 105.106... Data bus, 1
07.108.109...Data group write signal line, 110,111,112...Data read signal line, 113...Reading of each sector on the disk is completed The signal line that notifies you of what has happened, 114...
...Signal line that informs whether the data on the disk has been read correctly, 115...Output signal line of D flip-flop 3, 118, 119...Sevent signal line. Attorney Susumu Uchihara, Patent Attorney, Commissioner of the Japan Patent Office, 1, Indication of Case: 1982 Patent Application No. 128410
No. 2.9'^ Name of name Disk holder j 1111 Device f~
3) NEC Corporation Representative Tadahiro Sekimoto 4, Agent Address: 1084 Sumitomo Sanda Building i*Electric Co., Ltd., 5-37-8 Shiba, Minato-ku, Tokyo (6'591) Patent Attorney Uchihara Plain Phone Tokyo (03) ) 456-3111 (main representative) (contact address: NEC Corporation Patent Department) 5. Date of amendment order Akio [Today, October 158, 6] Target of amendment 7. Drawings of self-response and consultant for amendment Figure 2 has been replaced with Figure 2 of Annex 41 of the Gold Book of Procedural Amendments. Ni\, Agent Patent Attorney Uchihara Tomo 1.1・゛, Ni-4

Claims (1)

[Claims] A disk control/stem GC2 having a function of holding all information regarding sectors on the disk, controlling the reading operation of data included in the sector based on the information, and checking whether the data has been read correctly for each sector. a buffer for temporarily storing the data, a signal line for informing that reading of the sector containing the data has been completed, a signal line for informing whether the data has been read correctly, and information on these signal lines. When the reading of the sector containing the data is completed and the data is read correctly, the buffer outputs the data, and when the data is not read correctly, the buffer outputs the data. t- A disk control device characterized by comprising: means for preventing.