JPH04217017A - Memory extension method for semiconductor disk device - Google Patents

Abstract

PURPOSE:To extend a semiconductor memory to a semiconductor disk device used as the high-speed external storage device of a computer system without giving any influence on the operations of the computer system. CONSTITUTION:A table 10 provided with a column for recording track numbers at every logical drive and another column for recording addresses for indexing each track or symbols indicating unassigned states of the tracks is provided in devices 4 and 5 which use the space of a memory 14 as plural logical drives and perform data writing/readout based on logical drive numbers and track numbers and assigned memory addresses of each track are recorded in the address column of the memory corresponding to each track number of the logical drives which are increased in capacity due to an increase in the capacity of the memory 14 for accessing the increased area.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a semiconductor disk device used as a high-speed external storage device for a computer system, and in particular, it is possible to expand semiconductor memory used as a storage medium without affecting the operation of the computer system. The present invention relates to a method for adding memory to a semiconductor disk device.

[0002] With the spread of huge online systems, high-speed external storage devices are required. For this reason, along with magnetic disk devices that use conventional magnetic storage media,
Semiconductor disk devices that use semiconductor memory as a storage medium that does not require mechanical operation have appeared.

This semiconductor disk device generally arranges the entire built-in memory in one memory space, logically divides the memory based on setting information given from a switch or ROM, etc., and divides the memory from the user's perspective. In such cases, it is customary to make it appear as if there are multiple magnetic disk devices (emulation). Each emulated magnetic disk device is called a logical drive.

[0004] By the way, users select the capacity of the logical drive according to the circumstances of their individual work, and use the switch or R
Although memory is divided by OM or the like, when increasing the capacity of a logical drive, it is necessary to do so without affecting the operation of the computer system.

[0005]

2. Description of the Related Art FIG. 4 is a diagram illustrating an example of a conventional technique. In a conventional semiconductor disk device, as shown in FIG. 4, the arrangement of logical drives is such that a continuous area in the direction of increase in addresses shown by the arrow of the semiconductor memory is divided based on information set in a switch or ROM, etc. Assuming that there are three logical drives, logical drive 1 is allocated from address 0 to address X-1, logical drive 2 is allocated from address X to address Y-1, and logical drive 3 is allocated from address Y to the last address. Even the street address has been assigned.

As mentioned above, in a semiconductor disk device, the capacity of the logical drive is selected according to the user's individual circumstances, and the total capacity of the semiconductor memory required is determined. However, the semiconductor memory is generally a printed board unit. A plurality of printed board units are mounted on the device corresponding to the total capacity.

[0007] Therefore, when it becomes necessary to increase the capacity of a logical drive, the required amount of printed board units are added and mounted on the device to cope with the increase in capacity of the logical drive.

[0008]

[Problems to be Solved by the Invention] For example, when it becomes necessary to increase the capacity of the logical drive 2 shown in FIG. final address Y-
It is necessary to make address 1 even larger.

[0009] Therefore, it is necessary to change the starting address Y of the logical drive 3, but in order to make this change, it is necessary to turn off the power to the semiconductor disk device or at least take it offline.

[0010] However, the semiconductor disk device is the core of the computer system, and there is a problem in that by going offline, it becomes necessary to stop the entire computer system.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to make it possible to increase the capacity of a logical drive while keeping a semiconductor disk device online.

0012

[Means for solving the problem] And this purpose is shown in Figure 1.
As shown in , the space of the semiconductor memory 14 is divided into a plurality of areas, each area is allocated as logical drives 1 to 3, and the designated semiconductor memory is allocated based on the logical drive number and track number sent by the host device. In the disk control device 4 and semiconductor disk device 5 that access 14 areas to write/read data, track numbers up to the maximum number allowed for each logical drive 1 to 3 are recorded for each logical drive 1 to 3. a column for recording an address on the semiconductor memory 14 for indexing each track corresponding to the track number, and a column for recording a symbol indicating that the track is unallocated. 10 is provided, and for each of the logical drives 1 to 3, the address column of the semiconductor memory 14 of the table 10 corresponding to the unallocated track number exceeding the number of allocated tracks is as follows:
The unallocated symbols are recorded, and in the address column of the semiconductor memory 14 corresponding to each track number of the logical drive whose capacity has increased as the memory capacity is expanded, the symbols of each assigned track are recorded instead of the symbols. This is achieved by recording the memory address to access the additional area.

[0013]

[Operation] By configuring as described above, it is possible to obtain the address of the semiconductor memory 14 by referring to the table 10 based on the logical drive number and track number sent by the host device, and to write/read data. For,
When a printed board unit is added to the semiconductor disk device 5, the memory address column of the table 10 can be changed from the operator panel of the disk controller 4 so that the area of the added semiconductor memory 14 can be specified.

Therefore, there is no need to take the disk control device 4 and the semiconductor disk device 5 offline, and the capacity of the logical drive can be increased while they remain online.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a circuit showing one embodiment of the present invention. The processor 11 of the disk controller 4 reads and operates the program stored in the control memory 9, controls the interface circuit 6, the data transfer control circuit 7, and the interface circuit 8, and controls the communication between host devices such as channels and semiconductor disk devices. Controls data transfer to and from 5.

When the host device writes data to the semiconductor disk device 5, it sends out a logical drive number, track number, and sector number as addresses. processor 1
1 receives the write command and address sent by the higher-level device via the interface circuit 6, and since there is no mechanical operation, the interface circuit 6 immediately sends a data sending request to the higher-level device, and the control memory 9 is provided with a data sending request. Referring to table 10, the address of semiconductor memory 14 corresponding to the designated track number of the designated logical drive number is read.

FIG. 2 is a diagram illustrating an example of a table. As shown in FIG. 3, the table 10 includes a column for recording the logical drive number, a column for recording the track number up to the maximum number allowed for this logical drive corresponding to this logical drive number, and a column for recording the track number up to the maximum number allowed for this logical drive. Correspondingly, there is provided a column for recording the starting address of where in the memory space of the semiconductor memory 14 each track is developed.

Assume that the logical specifications of the magnetic disk device to be emulated by the semiconductor disk device 5 are as follows, for example. Maximum number of tracks
256 tracks 1 track capacity 1
1000 bytes (4K bytes) in hexadecimal number Also, assuming that the number of logical drives is 3 and the number of tracks initially allocated to each logical drive 1 to 3 is 16 tracks, the logical drive number corresponding to logical drive 1 "0" is recorded in the column, "0" to "255" are recorded in the track number column corresponding to this logical drive number "0", and track numbers "0" to "15" correspond to each track. The start address of the storage area of the semiconductor memory 14 corresponding to the number is written in hexadecimal as "00000" in the start address field.
000” to “0000F000” are recorded, and track numbers “16” to “255” are all symbols indicating that the tracks are unallocated, that is, “FFFF” in hexadecimal.
FFFF” is recorded.

The same applies to logical drive number "1" and logical drive number "2" corresponding to logical drives 2 and 3, but as shown in the figure, the logical drive number
The first address field of “1” is the logical drive number “0”
The hexadecimal numbers "00010000" to "0001F000" follow the addresses assigned to the 16 tracks of the logical drive number "2", and the address field of the logical drive number "2" follows the addresses assigned to the 16 tracks of the logical drive number "1". , hexadecimal “00020000”~”
0002F000”.

The processor 11 sends the address and sector number of the semiconductor memory 14 read from the table 10 with the contents shown in FIG. 3 to the transfer control circuit 13 of the semiconductor disk device 5 via the interface circuit 8 along with a write command.

The data transfer control circuit 7 also receives data sent from the host device via the interface circuit 6,
After being stored in the buffer memory, it is sent to the transfer control circuit 13 of the semiconductor disk device 5 via the interface circuit 8.

Therefore, the transfer control circuit 13 causes the transferred data to be written from the specified sector number of the specified address of the semiconductor memory 14. For example, if the host device specifies "1" as the logical drive number, "2" as the track number, and "3" as the sector number, the processor 11 determines the address of the semiconductor memory 14 from the table 10. "00012000"
and sends this address and sector number "3" to the transfer control circuit 13.

Therefore, the transfer control circuit 13 transfers the address "
Data is written from an address in the semiconductor memory 14 obtained by adding an address obtained from a predetermined sector length to "00012000".

When the host device reads data from the semiconductor disk device 5, it uses the logical drive number as an address,
The track number and sector number are sent out. When the processor 11 receives the read command and address sent by the host device via the interface circuit 6, it refers to the table 10 provided in the control memory 9 and determines the read command and address that correspond to the specified track number of the specified logical drive number. Read the address of the semiconductor memory 14.

The processor 11 sends the address and sector number of the semiconductor memory 14 read from the table 10 to the transfer control circuit 13 of the semiconductor disk device 5 via the interface circuit 8 along with a read command.

Therefore, the transfer control circuit 13 has the same functions as described above.
By adding a predetermined address from the specified sector number to the specified address of the semiconductor memory 14,
Data is read from the designated sector number and sent to the data transfer control circuit 7 via the interface circuit 8.

The data transfer control circuit 7 receives the data sent by the transfer control circuit 13 via the interface circuit 8, stores it in the buffer memory, and then sends the data via the interface circuit 6 to the host device.

[0028] If the host device specifies "1" as the logical drive number, "16" as the track number, and "3" as the sector number, then
The processor 11 has the table 10 address "FFF"
FFFFF", it is reported to the higher-level device via the interface circuit 6 that the specified track number is unallocated and does not exist.

For example, when a user mounts a printed circuit board unit in order to increase the capacity of the logical drive 2 and issues an instruction to rewrite the table 10 from the operator panel 12, the processor 11 responds to the instruction from the operator panel 12. Based on this, the address column of table 10 is changed.

FIG. 3 is a diagram illustrating the changed table. If 16 tracks are added to logical drive 2, the logical drive number will be ``
"00030000" to "0003F000" instead of "FFFFFFFF" are recorded in the head address fields corresponding to track numbers "16" to "31" of "1".

[0031]Updating of this table 10 can be carried out during online operation, and since it is also possible to mount a printed board unit, it will not affect the computer system.

[0032] Then, from the host device "16" to "3"
By specifying a track number of 1", the area of the expanded semiconductor memory 14 can be accessed. In this embodiment, the contents of the table are updated from the operator panel, but it is not necessary to configure the table. Of course, the ROM etc. may be replaced.

[0033]

[Effects of the Invention] As explained above, the present invention enables the disk control device and the semiconductor disk device to be kept online.
Since the capacity of the logical drive can be increased, there is no need to stop the computer system, and the effect is great.

[Brief explanation of the drawing]

[Fig. 1] Block diagram of a circuit showing one embodiment of the present invention

[Figure 2] Diagram explaining an example of a table

[Figure 3]
Diagram explaining the changed table

[Figure 4] Diagram explaining an example of conventional technology

[Explanation of symbols]

1, 2, 3 Logical drive 4 Disk control device 5 Semiconductor disk device 6, 8 Interface circuit 7 Data transfer control circuit 9 Control memory 10 Table 11 Processor 12 Operator panel 13 Transfer control circuit 14 Semiconductor memory

Claims (1)

[Claims] Claim 1: The memory (14) space is divided into a plurality of areas, each area is allocated as a logical drive (1) to (3), and a specified drive is performed based on the logical drive number and track number sent by the host device. In a device (4, 5) that writes/reads data by accessing a memory area that has been accessed, for each logical drive (1) to (3), the maximum allowable A column for recording track numbers up to a number, an address on the memory (14) for indexing each track corresponding to the track number, and a symbol indicating that the track is unallocated. Table with columns to (10)
For each of the logical drives (1) to (3), the address column of the memory (14) of the table (10) corresponding to the unallocated track number that exceeds the number of allocated tracks contains the unallocated track number. Record the assignment symbol and store it in memory (
14) In the address column of the memory (14) corresponding to each track number of the logical drive whose capacity has increased due to capacity expansion, record the memory address of each track assigned instead of the symbol, A method for expanding memory in a semiconductor disk device, the method comprising accessing an area.