JPS59105160A - Floppy disk controller - Google Patents

Abstract

PURPOSE:To improve the reliability and efficiency of a system by storing the status change of a ready signal indicating the operation ready status of a floppy disk device and the status signal indicating no selection of the floppy disk device. CONSTITUTION:Signals 36 are successively selected periodically and sent to respective floppy disk devices 25-28 as floppy disk selecting information through a floppy disk interface 18 and a control line 23. Status signals 37 successively sent from the respective floppy disk devices 25-28 are stored in a status storing circuit 21. An abnormal status detecting signal 36 to be outputted during the period of no selection of the floppy disk device is outputted from a decoder circuit 19 to detect the abnormal status. In order to detect the disk displacing operation, the status change of a ready signal indicating the operation ready status is stored in the status storing circuit 21.

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a floppy disk controller, and particularly to a floppy disk controller that controls a floppy disk device and exchanges information with a floppy disk based on control information from a host system (equipment with a built-in microcomputer). This is related to 1-. [Technical aspects and problems of the invention] Floppy disk controllers usually control one to several floppy disk devices using multiple operation signals. With conventional floppy disk controllers, the status information of each floppy disk device is output from the floppy disk controller or the floppy disk device selector according to a command from the host system, and the status information is obtained from the corresponding floppy disk device. It is carried out. Therefore, the post system can only obtain information about the state [y] at the time the command is sent. Therefore, in order to detect changes in the state of the floppy disk device that occur when replacing disks, periodically send command 011 from the host system to monitor the status 't:: '
There was an electrocardiogram. Also, if the state 'rr' + 7 vision is
Instead, each disc recorded songs and other data, and each time information was exchanged with the disc, processing was performed such as requesting disc identification data.
In such conventional floppy disk controllers, the software processing for the floppy disks on the Boston Sdem side is complicated, and there is a problem in that the time required for exchanging information with the floppy disks becomes long. In addition, as shown in Figure 1, the floppy disk ÷ the floppy disk from the floppy disk controller

[,,) 24
Floppy disk from H
One state lt+j information is outputted from three selected circuits 1.48 to 4D and outputted through open collector output circuits 5A to 51). , these output circuits 5A to 5D (or wired OR circuits with other floppy disk devices? If the output circuit of a disk device becomes defective, the output signals of all connected floppy disk devices will be f;, g jH:,:
; Missing “b” that causes reading errors from the input disk.
1. [Object of the Invention] The present invention is based on 111. □It was done by looking at it, Part 1” Published by Opost System (1j)
``The software processing related to the Combi Disk became obsolete, and the Fronbie Disc device outputted abnormally (-3
It is an object of the present invention to provide a floppy disk controller that can prevent defective data from being stuck to the disk and improper reading caused by the problem. [Force 1 [January] +a <, -re) Thursday Takuaki received 111 ri Jli information from the post system (one of which was equipped with a microcomputer) j) Shihi・I-t'r +lj interchange・
A floppy disk control to increase the level of control (in the Coke, the command from the host system is received, and when the floppy disk device is ordered locally, a selection message is determined. counter and the floppy disk device... t4M (+ii+ready indicating completion)
Status of the floppy disk device 1. ′:Zj, and a third memory circuit that stores the state I code when the selection signal does not select any floppy disk device. One knobby disc controller to the front end 3-. [Fruit of invention 1j'ff1e! l) FIG. 2 is a block diagram showing an embodiment of the floppy disk controller of the present invention. In FIG. 2, when the host system 13 issues a 4-redundant or 111-key request command to any of the floppy disk drives 25 to 28, the instruction information +lI! ! i, data,
The signal is input to the floppy disk controller 12 via the address line 14 and enters the floppy disk control circuit 17 through the Cr'tJ interface 16. The floppy disk 1trl a11 circuit 17 receives command information from the host system 13,
The command information is 1, (, and the floppy disk selection signal 29 is output. The floppy disk selection signal 29 (, -1, is decoded by the decoding circuit 19 to the signal 36, and the floppy disk interface 18 is output. Connect the disk control line 23 to 1Iljl,
and input to the floppy disks 25-28. For the floppy disk device compatible with floppy disk selection number 29, input the floppy disk system (lki1 circuit 17 to the floppy disk system ?dll signal 32 through the floppy disk interface 18 floppy disk control line 23). ] rt+-114 The iris 32 is made to perform the eight-point operation 1.-1', and the floppy disk status signal and data number are successively output. Floppy disk input (through the face 18, floppy disk type) Ma Iha No. 37 and data L-; ):
33 and 1 are input manually to the floppy disk control circuit 17, and the floppy disk output information is output to the floppy disk system? The signal is output from the iM circuit 17 to the host system 13 via the CPTJ interface 6 and the output data line 5. Next, when the floppy disk controller 12 is in a state of receiving commands from the host system (11), the control circuit 7 outputs a floppy disk Z selection switching signal 30, and the output signal 36 of the decoding circuit 19 is used as the floppy disk selection signal 36 of the counter 20. Switch to signal 31. FIG. 3 is a detailed circuit diagram of the periphery of the decoding circuit 19 and the state storage circuit 21, and FIG. 4 is a time chart for explaining the operation thereof. The signal 31 of the counter 20 consists of 3 bits and is input to the decoding circuit 19 as a periodically changing signal as shown in FIG. Turn on the switching circuit 19A and connect the stock as described above.
The signal 30 is overridden by the protection signal 30, decoded, and output as a floppy disk selection signal 36. This (A
No. 36 consists of 4-bit 4a No. 368 to 36J), and as shown in FIG. The floppy disk selection No. 48 36A to 361N, :t sequentially outputs a LOW signal for a period of pulse width T, and sequentially sends out from each floppy disk device jt25 to 28. 37 is stored in the state storage circuit 21. The state storage circuit 21 stores each state signal 37 sent from each floppy disk device at the timing of the floppy disk selection signals 36A to 36D. In addition, the decoding circuit 19 outputs an abnormal state detection signal 36E that outputs (, -i) during a period in which none of the floppy disk drives (d) is selected. No. 10 produces 16 different states.In other words, the 1st state of state 81B No. 37 is river, and the state 812 of state 7 is 7.11.
Assuming that an abnormal state occurs at step 2, the abnormal state M2 is stored in the state storage circuit 38 as the memory content 38Y at time t3 according to the timing of the signal 36E, as shown in FIG. In addition, the operation mulberry (
The state change of the ready signal indicating completion of iii is recorded in the state storage circuit 21 as follows. That is, FIG. 4 shows a case where the floppy disk device selected by the floppy disk selection signal 36A is in the process of disk switching 1 (p, 4'i44), and the ready signal 37A in the status signal 37 is OW. OR gate 4.2A when the state changes to
When the human power condition is satisfied, the state change detection signal 43A of the ready signal is stored in the D-type flip-flop 41A at the timing t. This state change detection (n'S 43
A is the switching signal 30 in dB order from the host system 13.
It is self-retained until it is output. The reason for the above explanation (2. The state memory circuit 21 is I:!:
J 4tjJ Always by the signals 36A to 36E generated; "X': New state 7g (H" The stored contents of the circuits 38, 39A to 39D can be output to -7 through the signal line 22. [Effects of the Invention] The floppy disk controller of the present invention can output the state information of the floppy disk device and the state of the ready signal. Change information and different γi + It becomes possible to prevent defective writing and defective reading due to the generation of abnormal signals, and it is possible to obtain a floppy disk controller with improved reliability.

[Brief explanation of the drawing]

Figure 1 is an input/output circuit diagram regarding status signals of a general floppy disk controller and a floppy disk device.
FIG. 2 is a block diagram showing an embodiment of the floppy disk controller of the present invention, FIG. 3 is a detailed circuit diagram of the state storage circuit and its surroundings, and FIG. 4 is a time chart for explaining its operation. 12... Floppy disk controller 13...
Host system 16...CPU interface 17...Floppy disk control circuit 18...Frombie disk interface 19...Decoding circuit 20-...Counter 21.38.3'JA~39
I)...Status record '1, 6 times [烙z5~28・Floppyde Isk Soukuri] 7'1~4], f-
)...D flip-flop 42A~421)...(
Negative logic input) OR gate (7:H7') Agent Patent attorney Rule Chika: I・! Haka 8 people ζ': 53 Figure 70 Figure 4

Claims (1)

[Claims] In a floppy disk controller that controls a floppy disk device and exchanges information using control information from a host system (equipment with a built-in microcomputer), the floppy disk device is periodically activated while waiting for an instruction from the post system. A counter that determines selection number 48 to be selected sequentially and a state change of a ready signal indicating that the floppy disk device is ready for operation are described.
a second storage circuit that stores the status signal of the floppy disk device; and a third storage circuit that stores the status signal when the selection signal does not select any floppy disk device. A floppy disk controller characterized by being provided with a memory circuit.