JPH04235632A - Program loading method - Google Patents

Abstract

PURPOSE:To easily update a program without storing a main program in a ROM even though the memory cost of a device is reduced and also a single body of device is sold to an OEM user. CONSTITUTION:A program loader end a memory card 3 storing an updated program are loader into a device. The address area of a nonvolatile memory EPROM contained in the card 3 is set in an enable state. Then the address area of a flash type EPROM (FEPROM) 2 is also set in en enable state. Under such conditions, the program loader erases totally the storage contents of the FEPROM 2 end then the updated program stored in the address area of the EPROM of the card 3 is transferred into the address area of the FEPROM 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program loading method for a device operated under microcomputer control.

0002

2. Description of the Related Art In devices that operate under conventional microcomputer control, a program loader is generally stored in a read-only memory (ROM), and the main program transmitted from a host control device is transmitted by the program loader through a transmitting/receiving circuit. This loads the main program into random access memory (RA).
M).

0003

[Problems to be Solved by the Invention] As mentioned above, since the conventional device requires RAM and ROM,
There is a problem that the cost of memory increases.

[0004] Furthermore, in order to load a program from a host control device (sometimes a magnetic disk device),
When selling a single device to an OEM user,
In many cases, loading from a higher-level control device made by another company with different standards cannot be expected. In such a case, it is necessary to store the main program itself in the ROM. In this case, the program must be updated by replacing the ROM, which poses the problem of necessitating the cost of remanufacturing the ROM and replacing the ROM.

The present invention was devised in view of these problems of the prior art, and it reduces the memory cost in the device.
Another object of the present invention is to provide a program loading method that allows the program to be easily updated without storing the main program in the ROM even when the device is sold to an OEM user.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention installs a memory card storing a program and a program loader in the above device, starts the program loader in the memory card, A system in which the programs stored in a storage means that can be erased all at once in the device are erased all at once, and then the program stored in the memory card is read out and transferred to and stored in the storage means in the device. It is.

[0007]

[Operation] According to the present invention, programs can be updated simply by installing a memory card.
There is no need to have OM, etc.), and memory costs can be reduced. In addition, even when selling a single device to an OEM user, there is no need to store the main program in ROM, and the program can be easily updated using a memory card.

[0008].

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a device that operates under microcomputer control according to the present invention. As shown in FIG. 1, the device of this example has the following features:
A microprocessor 1 and an electrically erasable flash EPROM (hereinafter referred to as FE) that stores programs.
(referred to as PROM) 2, a removable memory card 3 equipped with an EPROM, and a memory control 4.
It is composed of an inverter 5, a bus 6, and a RAM 11. The flash type EPROM can be electrically erased all at once, and is currently the lowest cost memory for storing programs.

Here, the bus 6 includes a data bus, an address bus, and a control bus through which control signals such as read/write signals are passed.

Further, the input side of the inverter 5 having a pull-up resistor of voltage Vcc is connected to ground via a wiring pattern within the memory card 3 only when the memory card 3 is connected. Therefore, the inverter 5 outputs the memory card 3 as the memory card connection presence/absence signal 7.
When the memory card 3 is connected, it outputs "1", and when the memory card 3 is not connected, it outputs "0". Memory card connection presence signal 7 output from inverter 5
is input to the memory control circuit 4.

The memory control 4 receives the memory card presence/absence signal 7 and determines that the memory card presence/absence signal 7 is "1".
”, the chip enable signal 8 is output to the FEPROM 2, and when the memory card presence/absence signal 7 is “0”, the chip enable signal 9 is output to the memory card 3. An erase control signal, a write control signal, and a mode control signal are respectively output to the FEPROM 2 via the FEPROM 2.In addition, during normal operation, the chip enable signals 8 and 9 are output from the inverter 5 as described above. One of the chip enable signals 8 and 9 is set to "1" depending on the memory card presence/absence signal 7, and both chip enable signals 8 and 9 are set to "1" when executing a program copy, which will be described later.

That is, chip enable signals 8 and 9 are signals generated by decoding the address bus assigned to address area A, and during normal operation,
The memory card connection presence/absence signal 7 enables the address area A of the FEPROM 2 when the memory card is not connected as shown in FIG. 2, and enables the address area A of the EPROM of the memory card 3 when the memory card is connected as shown in FIG. is enabled. Therefore, memory card 3
is not connected, microprocessor 1
The microprocessor 1 executes the program stored in the OM2, and when the memory card is connected, the microprocessor 1 executes the program stored in the EPROM of the memory card 3. Note that during program copy execution, as shown in FIG.
Address area A of OM and address area B of FEPROM 2 (another area that does not overlap with address area A) are enabled.

Next, the operation when executing a program copy will be explained. In this case, the EP in memory card 3
It is assumed that a program loader and an update program are stored in the ROM, and this memory card 3 is installed in the device. In this case, as mentioned above, the EP in the memory card 3
ROM address area A is enabled and FE
Address area B of PROM2 is enabled. In this state, the program loader erases the memory contents of the FEPROM 2 all at once, and then erases the EPR in the memory card 3.
Reads the update program stored in address area A of the OM, and transfers the read update program to the FEPROM.
2 in address area B.

Therefore, with this configuration, even if the device does not have a non-volatile memory (such as an EPROM) for storing the program loader, by connecting the memory card 3, the program loader can be stored in a part of the EPROM in the memory card 3. By executing the program loader and transferring data from address area A to address area B, the update program in the EPROM of the memory card 3 is transferred to the FEPR.
Can be written to OM2.

Note that if the address size of the microprocessor 1 is insufficient and two address areas cannot be defined, the RA connected to the bus 6 of the microprocessor 1
For M11, from EPROM in memory card 3
The program loader is transferred to the AM 11 and executed on the RAM 11. Next, RAM
11 as a work memory, set the chip enable signal 8 to "0" and the chip enable signal 9 to "1", enable only the EPROM of the memory card 3, read the update program from the address area A, and read the update program from the RA.
Transfer to M11. Next, the chip enable signal 8 is set to "1", the chip enable signal 9 is set to "0", and the FE
Enable only PROM2 and read from RAM11 to FEP
Transfer data to ROM2. This will allow you to copy the updates. Note that when the address area of the RAM 11 is small, the update program may be copied multiple times.

As is clear from the above description, according to this embodiment, programs can be updated simply by connecting the memory card 3 without requiring any other special program loading device. be able to. Also,
There is no need to have memory such as ROM for the program loader.

Furthermore, when updating a program, the program stored in the EPROM of the memory card 3 can be changed to a new program, and the program of the device can be updated on-board using the memory card 3.
Compared to ROM, the cost associated with changes can be reduced.

[0018]

As is clear from the above description, according to the present invention, it is possible to reduce the memory cost in a device controlled by a microcomputer, and even when the device is sold alone to an OEM user, the main program can be stored in the ROM. It is possible to provide a program loading method that does not require storing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the hardware configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a memory map of the microprocessor shown in FIG. 1;

FIG. 3 is an explanatory diagram showing a memory map of the microprocessor shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a memory map of the microprocessor shown in FIG. 1;

[Explanation of symbols]

1...Microprocessor 2...FEPROM 3...Memory card 4...Memory control 5...Inverter 6...Bus 7...Memory card presence/absence signal 8...Chip enable signal 9...Chip enable signal 10...Signal line 11...RAM

Claims (1)

[Claims] 1. A program loading method for a device that operates under the control of a microprocessor, comprising: loading a memory card storing a program and a program loader into the device; activating the program loader;
Batch erasing the programs stored in the batch erasable storage means in the device, then reading out the programs stored in the memory card, and transferring the read programs to the storage means in the device and storing them. A program loading method characterized by: