JPH0876989A - Electronic apparatus driven by program and rewriting method for program - Google Patents

Abstract

PURPOSE: To easily rewrite a program for controlling an electronic apparatus such as a magnetic tape device. CONSTITUTION: A magnetic tape device 1 is provided with a data recording/ reproducing device 2, a CPU 4 for controlling the device 2, a flash PROM 5, and a RAM 6. A main program for controlling the device 2 is stored in an area 5a of the PROM 5 and a rewriting program is stored in an area 5b. At the time of rewriting the main program, the rewriting program is transferred to the RAM 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program controllable electronic device such as a magnetic tape device and a program rewriting method.

[0002]

2. Description of the Related Art For example, a backup magnetic tape device (streamer) as an external storage device of a computer system such as a personal computer may be configured to be program controllable. This type of magnetic tape device includes a magnetic tape drive device, a CPU (central processing unit), a RAM (random access memory), and a PROM (programmable read only memory) storing a control program (desired program).・ Memory) or EPROM (erasable P
ROM).

[0003]

By the way, there are cases where it is desired to change the control program of an electronic device such as a magnetic tape device. In this case, it is necessary to convert the old PROM or EPROM into a PROM or EPROM in which a new program is written, and this replacement requires considerable time and cost. Flash PROMs or EEPROMs may be used instead of PROMs or EPROMs. This flash PROM can be rewritten while the program is still installed in the electronic device. However, it is necessary to mount an individual memory storing a program for executing the rewriting of the program on the electronic device, which increases the number of parts of the electronic device and increases the cost.

Therefore, an object of the present invention is to provide an electronic device and a program rewriting method capable of easily rewriting a program stored in a rewritable nonvolatile memory while suppressing an increase in cost. is there.

[0005]

The present invention for achieving the above object provides an electronic device which operates according to a predetermined program, and an electronic device which is connected to the electronic device for operating the electronic device according to the predetermined program. CPU
And a RAM connected to the CPU, and a rewritable non-volatile memory connected to the CPU and the RAM, and the predetermined program is written in the rewritable non-volatile memory, The present invention relates to an electronic device in which a rewriting program for executing at least the rewriting of the predetermined program is prewritten. The invention according to claim 2 is an electronic device that operates according to a predetermined program, a CPU that is connected to the electronic device to operate the electronic device according to the predetermined program, and a CPU that is connected to the CPU. The rewritable non-volatile memory comprises a RAM and a rewritable non-volatile memory connected to the CPU and the RAM. The rewritable non-volatile memory stores the predetermined program and at least rewrites the predetermined program. A method of rewriting at least the predetermined program of the non-volatile memory in an electronic device in which a rewriting program to be executed is written in advance, comprising a step of giving a predetermined program rewriting command to the CPU, Rewriting of the rewritable non-volatile memory by the CPU in response to the rewriting command A program for transferring the program to the RAM, switching the CPU from an operation according to the predetermined program to an operation according to a rewriting program in the RAM, preparing a new predetermined program, and causing the CPU to rewrite the program in the RAM. And writing the new predetermined program in the rewritable non-volatile memory in accordance with the above method. As described in claim 3, a program rewriting command and a new program can be supplied from the host device. Further, as described in claim 4, a new program can be supplied from the recording medium.

[0006]

According to the invention of each claim, a rewritable non-volatile memory (for example, EEPROM) in which a predetermined program for controlling electronic equipment is stored.
Further, since the program for executing this rewriting is also written, the rewriting of a predetermined program can be easily executed at low cost.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic tape device as an external storage device of a computer system according to an embodiment of the present invention will be described below with reference to FIGS. The magnetic tape device 1 as an electronic device can be controlled by a SCSI program in addition to the recording / reproducing device 2 as an electronic device that can be controlled according to a predetermined program.
Interface 3, CPU (central processing unit) 4, rewritable nonvolatile memory (fixed memory) flash PROM (EEPROM) 5, and RAM (random memory)
Access memory) 6 and a bus 7, each coupled to bus 7.

The recording / reproducing device 2 which is the main body of the magnetic tape device 1 has a tape drive device 11 which is engaged with a pair of reels 10 around which a recording medium magnetic tape 9 of a tape cassette 8 is wound. The tape driving device 11 is a known device including a pair of reel motors, a tape speed detecting means, and a motor control circuit, and is configured to run the tape 9 at a substantially constant speed.

A recording magnetic head 12 for signal conversion and a reproducing magnetic head 13 are arranged along the running path of the tape 9.
A recording circuit 14 is connected to the recording head 12, and a reproducing circuit 15 is connected to the reproducing head 13. The recording head 12 and the reproducing head 13 are mechanically integrated,
It is composed of a composite head. Further, although not shown, means for moving the heads 12 and 13 in the width direction of the tape 9 (track crossing direction) to switch tracks is provided. The tape drive device 11 sends CP via the bus 7.
It is connected to U4 and controls the running, stopping, rewinding, etc. of the tape 9 in accordance with instructions from the CPU 4.

The recording circuit 14 is connected to the CPU 4 via the bus 7,
The data supplied from the host device 16 which is connected to the interface 3 and the like and is connected to the bus 7 via the interface 3 is recorded on the tape 9 according to a predetermined track format.

The reproducing circuit 15 is connected to the interface 3, the CPU 4, the flash PROM 5, and the RAM 6 via the bus 7, and when the tape cassette 8 is for reproducing the main data, this reproduced data is sent to the host device. If the tape cassette 8 contains a new program for rewriting, the data is sent to the flash PROM 5 via the reproduction data RAM 6.

The flash PROM 5 is a recording / reproducing device 2
It has a main program area 5a for storing a main program for controlling, and a rewrite program area 5b for storing a rewrite program used when rewriting the flash PROM 5. In the rewriting program area 5b, a first rewriting program for executing the rewriting of the main program based on the host device 16 and a second rewriting program for executing the rewriting of the main program based on the recording / reproducing device 2 are performed. Both the rewriting program is stored.

The main program here is, for example, as shown in FIG.
It is configured as shown in FIG. First, the program starts at block 20, then block 2
As shown in 1, it is determined whether or not a command is given from the host device 16. When the command is given from the host device 16, it is then determined whether or not the command is for executing the rewriting of the contents of the flash PROM 5 as shown in block 22. In the case of NO output indicating that rewriting is not necessary, as shown in block 23, the process shifts to the processing by the program for recording / reproducing the main data by the tape 9 of the recording / reproducing apparatus 2, and the recording / reproducing of the main data is executed. When this is completed, the process returns to block 21, and it is determined again whether or not there is a command. On the other hand, when it is determined in block 22 that the command indicates rewriting, as shown in block 24, the rewriting program area 5 of the flash PROM 5 is read.
The first rewriting program of b is transferred to the RAM 6. When it is determined in block 21 that the command is not from the host device 16, it is determined in block 25 whether or not the tape cassette 8 is now mounted in the recording / reproducing device 2. When the tape cassette 8 is mounted, the recording / reproducing apparatus 2 is initially driven in the next block 26.
That is, the reading of the head portion of the track T0 of the tape 9 is executed. A signal indicating whether or not the tape is a rewriting tape is recorded in the head portion of the track T0 of the tape 9. When it is determined in block 25 that the tape cassette 8 is not mounted, the process returns to block 21. Next, at block 27, it is judged based on the reproduction output from the tape 9 whether or not the tape cassette is a rewriting tape cassette. When it is determined in block 27 that the tape cassette is a rewritable tape cassette, block 2
8, a second rewriting program, that is, a program for executing the rewriting of the main program based on the recording / reproducing apparatus 2 is read from the area 5b of the flash PROM 5 to R.
Transfer to AM6. When it is determined in block 27 that the tape cassette is not the rewriting tape cassette, the process proceeds to block 23, and the processing by the program for data recording / reproducing is executed.

The program for recording / reproducing data (substantially the main program) shown in block 23 is
A program for writing the main data supplied from the host device 16 to the tape 9 according to a predetermined method and the tape 9
A program for reading out the main data recorded in the above in accordance with a predetermined method and sending it to the host device 16, for example, a program for error check at the time of recording, rewriting based on this error check, double recording control, etc. It is a program for error check, retry, etc. during playback.

Next, the first rewriting program for rewriting the main program based on the host device 16 and the rewriting operation according to the first rewriting program will be described. FIG. 3 schematically shows a first rewriting program written in the area 5b of the flash PROM 5. When the host device 16 issues a command to rewrite the contents of the flash PROM 5,
The first rewriting program is transferred to the RAM 6 according to the block 24 of FIG. 2, and thereafter, the operation according to the first rewriting program shown in FIG.
Since most of the RAM 6 is unused when the recording / reproduction of the main data on the tape 9 is not executed, the RAM 6 has a sufficient capacity for storing the rewriting program. When the rewriting program starts as shown in block 30 of FIG. 3, the flash PROM 5 is controlled to the writable state as shown in block 31. That is, the flash PROM 5
Erase the contents of and set the state where a new program can be written. Next, as shown in block 32, the host device 16 is notified that the writable state of the new program for the flash PROM 5 has been set. Upon receiving this notification, the host device 16 sends a new program to the tape device 1. At this time, the host device 16 side notifies the operator of the notice of the writable state of the tape device 1 by a display or voice. In response to this, the operator sends a new program from the host device 16.
The tape device 1 receives the new program as shown in block 33 and stores it in the RAM 6. Since the new program is usually larger than the storage capacity of the RAM 6, the new program is divided and sent from the host device 16 to the tape device 1. Next, as shown in block 34, RAM 6 to flash PROM 5
, A new main program is written in the area 5a, and a new rewriting program is written in the area 5b. As described above, since all the new programs cannot be stored in the RAM 6, the program 35 determines whether or not there is a next program, and if there is, returns to the program 32 to continue writing the new program. If there is no next program, the rewriting program is terminated as shown in block 36. It should be noted that after writing the new program to the flash PROM 5, the host device 16 is notified of this fact, and the host device 16 notifies the operator of this by a display or voice, and includes the host device 16 and the tape device 1. It is desirable to reset the entire system.

As is apparent from the above, since the rewriting program for rewriting the flash PROM 5 for the main program is stored, the dedicated ROM for the rewriting program becomes unnecessary and the magnetic tape device 1 Cost reduction is achieved. Also, rewriting of the main program can be easily achieved.

Next, writing of a new program based on the recording / reproducing apparatus 2 will be described. In the system of FIG. 1, a new program can be supplied from the recording / reproducing apparatus 2 instead of being supplied from the host apparatus 16. In this case, the tape 9 of the tape cassette 8 is prewritten with the new program by the system of FIG. 1 or by another system. That is, the tape 9 is written in the flash PROM 5 as a new program source.

Writing of a new program to the tape 9 is performed as shown in FIGS. 4 to 6, for example. Since the tape 9 has a large number of tracks T0 to T4 as shown in FIG. 4, it is the first track T0 after the reference track Tr.
Record the rewrite command in. Figure 5 shows the first track T
Multiple (4) data blocks D that are the first part of 0
Indicates that a rewrite command is recorded in B1 to DB4.
This rewrite command is made up of a plurality of data blocks DB1 to DB.
Repeat recording (multiple recording) on B4.

The data blocks DB1 to DB7 in FIG. 5 are formed in the format shown in FIG. 6, respectively, and include a sync signal (burst signal) area 41 and a gap area 42.
A control field area 43, a data field area 44, a CRC area 45, and a gap area 46.
It consists of and. The rewrite command is recorded in the control field area 43. The new program is recorded in the data field 44 after the data block DB5 in FIG.

The operation of supplying a new program from the tape 9 and writing it in the flash PROM 5 is as follows.
First, when the tape cassette 8 in which the new program is recorded is mounted in the recording / reproducing apparatus, the block 26 in FIG.
In order to judge the type of the tape 9, the reproduction of the track T0 of the tape 9 automatically starts. This allows
The rewrite command is read from the data blocks DB1 to DB4 of the first track T0 and sent to the CPU 4 via the reproducing circuit 15 and the bus 7. Block 2 of FIG.
When it is judged to be the rewriting tape cassette 27 in 7,
Area 5 of flash PROM 5 according to block 28
The second rewriting program of b is transferred to the RAM 6.

After that, the magnetic tape device 1 operates according to the second rewriting program of FIG. 7 transferred to the RAM 6. The rewriting program is a modification of part of FIG. 3, and when the program starts at block 50,
Next, in block 51, the flash PROM 5 is set to the writable state. Next, as shown in block 52, the recording / reproducing apparatus 2 is driven. Next, as shown in block 53, the new program obtained from the recording / reproducing apparatus 2 is stored in the RAM 6. Then, as shown in block 54, the new program in RAM 6 is flashed to PROM.
5, the new main program is written in the area 5a, and the new rewriting program is written in the area 5b. As already described with reference to FIG. 3, since the entire new program cannot be stored in the RAM 6, the new program is divided and stored in the RAM 6 and transferred to the flash PROM 5. Therefore, in block 55, it is judged whether or not there is a next program. When there is a next program, the process returns to block 52, and when there is no next program, all the operations are completed in block 56.

The rewriting method according to FIG. 7 has the same advantages as the method of FIG. 3 and also has the advantage that the program can be rewritten only by the magnetic tape device 1 without relying on the host device 16.

[0023]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) The interface between the host device 16 and the magnetic tape device 1 can be configured to use a floppy disk interface. (2) When the program rewriting command is sent from the host device 16 to an electronic device such as a magnetic tape device, a dedicated control signal line may be used in a time-division manner without using a dedicated control signal line. . (3) It is possible to rewrite only the main program in the area 5a of the flash PROM 5 and not rewrite the rewriting program in the area 5b. In this case, the rewriting program transferred to the RAM 6 is flashed from the RAM 6 before or after the rewriting of the main program.
It is desirable to return it to the area 5b of the ROM 5. (4) In the embodiment, when rewriting the main program based on the host device 16, only the first rewriting program is transferred to the RAM 6, and when rewriting the main program based on the tape 9, only the second rewriting program is RAM.
However, it is possible to transfer both the first and second rewriting programs to the RAM 6. (5) It is possible to rewrite only the program for data recording / reproducing in block 23 of FIG. (6) The present invention can be applied not only to the magnetic tape device 1 but also to various electronic devices such as a program-controlled magneto-optical recording device. (7) A similar rewritable fixed (non-volatile) memory can be used instead of the flash PROM 5.

[Brief description of drawings]

FIG. 1 is a block diagram showing a magnetic tape device according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a main program of the apparatus shown in FIG.

3 is a diagram schematically showing a first rewriting program of the apparatus of FIG.

4 is a plan view showing a part of a magnetic tape device for another rewriting method of the device of FIG. 1. FIG.

5 is a diagram showing a part of the track of FIG. 4. FIG.

FIG. 6 is a diagram showing a format of a data block of FIG.

FIG. 7 is a diagram schematically showing a second rewriting program.

[Explanation of symbols]

 1 magnetic tape device 4 CPU 5 flash PROM 6 RAM

Claims (4)

[Claims] 1. An electronic device operating according to a predetermined program, and a CPU connected to the electronic device for operating the electronic device according to the predetermined program.
And a RAM connected to the CPU, and a rewritable nonvolatile memory connected to the CPU and the RAM, and the predetermined program is written in the rewritable nonvolatile memory, An electronic device in which a rewriting program for executing rewriting of the predetermined program is prewritten. 2. An electronic device operating according to a predetermined program, and a CPU connected to the electronic device for operating the electronic device according to the predetermined program.
And a RAM connected to the CPU, and a rewritable nonvolatile memory connected to the CPU and the RAM, and the predetermined program is written in the rewritable nonvolatile memory, A method for rewriting the predetermined program in the non-volatile memory in an electronic device in which a rewriting program for executing the rewriting of the predetermined program is previously written, comprising: In response to the rewriting command, the CPU reads the rewriting program of the rewritable non-volatile memory and transfers the rewriting program to the RAM;
The method includes the steps of switching to an operation according to the rewriting program of AM, preparing a new predetermined program, and writing the new predetermined program into the rewritable nonvolatile memory by the CPU according to the rewriting program of the RAM. A program rewriting method characterized in that 3. The electronic device is used by being connected to a host device, and the CPU prepares a rewriting command of the predetermined program and preparation of the new predetermined program.
The program rewriting method according to claim 2, wherein the program rewriting method is performed by a host device connected to. 4. The electronic device comprises a recording medium, a signal conversion head, and a drive device for causing relative scanning movement between the recording medium and the head, and the predetermined device. To prepare the program rewriting command and the new predetermined program, a recording medium in which the predetermined program rewriting command and the new predetermined program are written is prepared, and from this recording medium, the head rewrite command and the new recording program are written by the head. The program rewriting method according to claim 2, wherein the predetermined program is read and sent to the CPU.