JPH09274798A - Writing method for electrically reloadable rom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing method by which program data can be written in many ROMs at once using a ROM writer after a printed substrate is mounted. SOLUTION: Interface parts which can make a CPU a sleep state and can externally control a flash ROM are provided in a CPU and a printed substrate 1 of a flash ROM, and a connecting means (conversion substrate 2) connecting this interface part and a ROM socket of a ROM writer 3 is provided. And the interface part and a ROM socket of a ROM writer 1 are connected through a connecting means in a state in which a flash ROM is mounted to the printed substrate 1, the CPU is made a sleep state, and program data is written in the flash ROM mounted to the printed substrate 1 from the ROM WRITER 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for writing an electrically rewritable ROM (Read Only Memory), and more particularly, to a method of mounting a device such as a CPU on a printed circuit board such as a facsimile control board together with a device such as a CPU which can be a bus master. The present invention relates to a method for writing program data to the ROM.

[0002]

2. Description of the Related Art Conventionally, written data can be erased using ultraviolet rays or the like and re-programmed (written).
PROM (Erasable Programmable)
e ROM) It is common to write a single item using a ROM writer.

Recently, a flash EEP of a batch erase type has been proposed.
ROM (Electric Erasable Pro)
grammable ROM; hereinafter simply flash R
OM) is widely used because its structure can realize a large capacity at a low cost, and a ROM writer has come to be compatible with this.

[0004] In addition, flash ROMs in flat packages have also been increasing for surface mounting, which can reduce the size of products.
A conversion board (socket) from an in-line package) to a flat package is also commercially available.

As described above, conventionally, the writing has mainly been performed for the ROM alone. And the ROM that has finished writing
Was mounted on a printed circuit board by soldering.

As a method of writing program data to a flash ROM or the like after being mounted on a printed circuit board, Japanese Patent Application Laid-Open Nos. 6-60682 and 6-23
As described in Japanese Patent Laid-Open No. 3023 and Japanese Patent Laid-Open No. 7-13753, there is a method of writing with a device that can be a bus master, such as a CPU, mounted on a printed circuit board.

[0007]

As described above, when a flash ROM or the like is written as a single item using a ROM writer, a flat packaged one is particularly suitable for a DIP / flat package conversion board ( When writing to the conversion board (socket), writing errors may occur due to poor contact with the conversion board (socket), or leads may be bent when removing from the conversion board (socket) after writing is completed. was there. Since the distance between the leads of the flat package is considerably smaller than that of the DIP, the bent R
When the OM is mounted (soldered) on a printed circuit board, problems such as poor soldering may occur.

After mounting, the CP on the printed circuit board is
When writing (downloading) using U, a program for performing this operation must be stored in another memory in advance. Also, the CP on the printed circuit board
Since I use U, I was able to write only one at a time.

Therefore, the present invention has been made in order to solve such a problem, and after mounting (soldering) on a printed circuit board, program data can be stored in many ROMs at once using a ROM writer. It is an object of the present invention to provide a writing method capable of writing.

In many cases, the ROM writer has a power supply capability only for the ROM itself, and therefore it is an object of the present invention to cope with the case where the power consumption current of the printed circuit board is large.

Further, since the ROM writer often has only the drive capability for the control signal to the ROM alone, it is an object of the present invention to cope with the case where the drive load for the control signal on the printed circuit board is large. is there.

[0012] Further, a plurality of ROs are provided on one printed circuit board.
Even if M is mounted, the purpose is to enable writing to these plural ROMs.

[0013]

In order to achieve the above object, the invention according to claim 1 of the present application is such that a device that can be a bus master and a ROM that is electrically rewritable are mounted on a printed circuit board. And a connection means for connecting the interface section and a ROM socket of a ROM writer, the interface section being capable of externally controlling a device that can become a sleep state and controlling the electrically rewritable ROM from the outside. And mounting the electrically rewritable ROM on the printed circuit board, connecting the interface section and the ROM socket of the ROM writer via the connecting means, and putting the device that can be the bus master into a sleep state. And electrically rewritable R mounted on the printed circuit board It is obtained so as to write the program data from the ROM writer M.

According to a second aspect of the present invention, in the first aspect, the connecting means is composed of a board, and the electrically rewritable ROM mounted on the printed board is mounted on the board. And an external power supply used for writing the data, and a power supply voltage tracking supply unit that supplies the external power supply voltage to the interface unit of the printed circuit board by following the power supply voltage supplied from the ROM socket of the ROM writer. .

Further, the invention according to claim 3 is the same as in claim 1 or 2, wherein the connecting means is composed of a substrate and is necessary for writing an electrically rewritable ROM on this substrate. Equipped with a signal buffer section,
The signal output from the ROM writer is supplied to the interface section of the printed circuit board via the buffer section.

On the other hand, according to the invention of claim 4, a device which can be a bus master can be put into a sleep state from the outside on a printed circuit board on which a device which can be a bus master and a plurality of electrically rewritable ROMs are mounted. An interface section is provided which can control the plurality of electrically rewritable ROMs from the outside, and the interface section and the ROM of the ROM writer.
A connecting means for connecting to the socket and a plurality of Rs capable of electrically rewriting the chip select signal from the ROM writer.
A plurality of electrically rewritable ROMs mounted on the printed circuit board, and the interface section and the ROM socket of the ROM writer. Program data from the ROM writer is connected to each of a plurality of electrically rewritable ROMs mounted on a printed circuit board by connecting the devices that can be bus masters to a sleep state. It was designed to write.

According to a fifth aspect of the present invention, in the fourth aspect, the connecting means is formed of a board to mount the chip select switching means, and the printed board is mounted on the board. An external power supply used to write a plurality of electrically rewritable ROMs in a state, and a power supply that supplies the external power supply voltage to the interface section of the printed circuit board following the power supply voltage supplied from the ROM socket of the ROM writer. And a voltage tracking supply section.

Further, the invention according to claim 6 is the same as in claim 4 or 5, wherein the connecting means is constituted by a substrate and the chip select switching means is mounted, and the electrical connection is made electrically on the substrate. Multiple rewritable ROs
A buffer unit for signals necessary for writing M is provided, and a signal output from the ROM writer is supplied to the interface unit of the printed circuit board via the buffer unit.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of each invention of the present application will be described in detail.

As shown in FIG. 1, the system configuration according to each embodiment of the present invention includes a printed circuit board 1 such as a facsimile control board, a conversion circuit board 2 having a pin assign conversion function as connecting means, and a plurality of conversion boards. ROM
It comprises a ROM writer 3 having a socket. Then, the program data is written from the ROM writer 3 to the flash ROM mounted on the printed board 1 via the conversion board 2.

As shown in FIG. 2, the configuration of the printed circuit board 1 according to the inventions of claims 1 to 3 of the present application is, as shown in FIG.
12 and a flash ROM control interface (I / F) 13 capable of controlling the flash ROM 12 from the outside.
And a power supply for operating the flash ROM 12, etc.
Printed wirings such as an address bus, a data bus, control signals such as read / write signals, and sleep signals for putting the CPU 11 into a sleep state (stop state) are formed. During normal operation, the CPU 11 flashes R
The OM 12 is controlled. When writing program data to the flash ROM 12, the flash ROM control I / F 13 puts the CPU 11 in a sleep state and externally controls the flash ROM 12.

FIG. 3 shows the structure of the conversion board 2 according to the embodiment of the present invention. The flash ROM control I / F 21 is connectable to the flash ROM control I / F 13 of the printed board 1, and FIG. R
The OM writer 3 comprises a ROM socket and a ROM writer I / F 22 connectable thereto. The power supply, address bus, data bus, and control signal are transferred from the ROM writer 3 to the printed circuit board 1
, And the sleep signal is fixed (GND level in the figure) so that the CPU 11 enters a sleep state.

In the above configuration, the flash ROM 1
The writing of the program data in 2 is performed as follows. First, the flash ROM control I / F 13 of the printed board 1 on which the flash ROM 12 is mounted by soldering and the flash ROM control I / F 21 of the conversion board 2 are connected by connectors. As a result, GND
The sleep signal fixed at the level (Low level) is C
When applied to the PU 11, the CPU 11 enters a sleep state (stop state), the flash ROM 12 is electrically disconnected from the CPU 11, and can be freely controlled from the outside. Next, the ROM writer I / of the conversion board 2
The connector provided in F22 is the ROM of the ROM writer 3.
Insert into the socket. Since the ROM writer 3 is usually provided with a large number of ROM sockets (for example, 8 rows each including 2 rows and a total of 16 ROM sockets), a plurality of the printed circuit boards 1 to which the conversion boards 2 are attached as described above are vertically arranged. R in the open state
It can be set on the OM writer 3.

By controlling the ROM writer 3 with the printed circuit board 1 set in this way as shown in the flowchart of FIG. 4, writing of program data to the flash ROM 12 is performed. Note that this processing is performed by the flash ROM 12 mounted on the printed circuit board 1.
Is the same as the case of writing the flash ROM alone which is inserted into the ROM socket.

That is, first, it is checked whether or not there is a flash ROM to be written (decision 101). If there is a flash ROM to be written, a write mode is entered to enable a control signal such as a write signal (process 102), and a write address and program data are output to an address bus and a data bus (process 103). Then, it waits until the write operation time elapses (decision 10).
4 N loops). When a predetermined write operation time has elapsed (Y in decision 104), a write check mode is entered to enable a read signal of a control signal and the like (step 10).
5) Read the write data from the flash ROM (process 106). Then, the read data is compared with the written data to check whether or not the data is correctly written (decision 107). If the data is not written, the process returns to step 102 and the above writing process is repeated. On the other hand, if the data has been written, the process returns to the first judgment 101 to check whether or not there is a flash ROM to be written, and the above processing is performed until the writing of all the ROMs set in the ROM writer 3 is completed. repeat.

According to the above, the program data can be written in the flash ROM 12 mounted on the printed circuit board 1 by the ROM writer 3, and a large number of flash ROMs 12 at a time can be generated without causing a defect such as a defective soldering. It becomes possible to write the program data to.

FIG. 5 shows the structure of the conversion substrate 2 according to the embodiment of the present invention as defined in claim 2. Only the part where the power supply voltage tracking supply part 23 is added in the middle of the power supply line is the same as in FIG. Of the embodiment of FIG.

As shown in FIG. 6, the power supply voltage follow-up supply unit 23 includes the ROM writer 3 to the ROM writer I / O.
DC power source 23a is supplied by the power source supplied through F22.
The output from is turned on / off by the relay 23b, and the printed circuit board 1
7 and the power supply voltage supplied from the ROM writer 3 via the ROM writer I / F 22, as shown in FIG. 7, using the operational amplifier 23c and the transistor 23d to output the output voltage from the DC power supply 23a. Control and
A configuration in which the printed circuit board 1 is supplied via the flash ROM control I / F 21 can be implemented. By using the DC power supply 23a having a sufficient power supply current capacity as the external power supply and having the above configuration, the printed circuit board 1
Even if the current consumption of the power supply is large, it can be supplied without any problem. 6 can be used when the ROM writer 3 outputs only a single voltage, or when the printed circuit board 1 requires only a single voltage, and the one in FIG. 7 can be used.
Can output several types of voltages and can be used when those voltages are also required for printed circuit boards. The write operation is the same as in the above embodiment.

FIG. 8 shows the structure of the conversion board 2 according to the embodiment of the present invention. The buffer section 2 is provided in the middle of the address bus, the data bus and the control signal line.
4 is different from that of the embodiment shown in FIG. The power supply of the buffer unit 24 is also supplied from the power supply voltage tracking supply unit 23. With the addition of the buffer unit 24, R
The load viewed from the OM writer 3 side is only the buffer section 24, and the load can be reduced.
It is possible to handle even when the drive load for the control signal and the like is large. The write operation is the same as in the above embodiment.

FIG. 9 shows the printed circuit board 1 according to claim 4.
8 is a block diagram showing a configuration according to the invention of claim 6; Here, two flashes R are provided on the printed circuit board 1.
An OMa12 and a flash ROMb25 are installed, and each flash ROMa12 and flash ROMb2
A power supply, an address bus, a data bus, and a control signal line similar to those in the above embodiment are connected to the chip 5, and a chip select a signal and a chip select b signal for selecting each chip are provided to the flash ROM controller I.
It is configured to be supplied from / F13. In addition,
Other configurations are the same as in the above embodiment.

The conversion board 2 corresponding to the printed board 1 has a structure as shown in FIG.
The chip select switching unit 26 is added to that of the above embodiment. This chip select switching unit 26 is used for the ROM writer 3 to the ROM writer I / F 22.
The chip select signal supplied via the switch is switched to either the chip select a signal or the chip select b signal and supplied to the flash ROM control I / F 21. The chip select switching unit 26 shown here may be a so-called jumper JP switching method as shown in FIG. 11 or a switch SW switching as shown in FIG. 12, which is relatively simple in any case. It can be realized at low cost.

The write operation of this embodiment is basically the same as that of the previous embodiment, but when program data is written to the flash ROM a12 on the printed board 1, the chip select switching section 26 (jumper) on the conversion board 2 is used. JP or switch SW) is set on the chip select a signal side, and when writing to the flash ROM b25, it may be switched to the chip select b signal side. With such a configuration, the same effect as that of the embodiment of FIG. 8 can be obtained, and the RO shown in FIG.
Even in the printed circuit board 1 on which a plurality of M's are mounted, the program data can be written.

In the present embodiment, the description has been made by switching between the chip select a signal and the chip select b signal. However, if the chip select switching section 26 can switch three or more, three chips are selected. RO above
The same writing can be performed on a printed circuit board on which M is mounted.

Further, in this embodiment, the chip select switching unit 2 is provided on the conversion substrate 2 shown in the embodiment of FIG.
6 has been described, the same effect can be obtained even if the conversion substrate 2 shown in the embodiment of FIGS. 3 and 5 is provided. Further, this chip select switching unit 26 is similar to that shown in FIG.
Since it can be realized relatively easily and inexpensively as shown in FIG. 1 and FIG. 12, it can be implemented by providing it on the printed circuit board 1 itself.

Further, in the present embodiment, the chip select signal is switched by the chip select switching section 26 and supplied to one of the plurality of ROMs, and the problem of drive load does not occur. However, the buffer 24 may be used as one of the control signals.

By the way, in each of the above-mentioned embodiments, the inventions of the present application are implemented by a batch erasing type electrically rewritable RO.
Although the case where the present invention is applied to a flash ROM of M has been described, any electrically rewritable ROM can be applied not only to the batch erase type but also to a normal EEPROM.

The inventions of the present application can be applied not only to the fax control board as the printed circuit board but also to various control boards equipped with devices that can be bus masters. In addition, as a device that can be a bus master, there is a DMA controller in addition to the CPU.

[0038]

As described above, according to the invention of claim 1 of the present application, the device that can be the bus master is externally mounted on the printed circuit board on which the device that can be the bus master and the electrically rewritable ROM are mounted. The printer includes an interface unit that can be brought into a sleep state from the outside and can control the electrically rewritable ROM from the outside, and a connection unit that connects the interface unit and the ROM socket of the ROM writer. With the electrically rewritable ROM mounted on the substrate, the RO of the interface unit and the ROM writer
Since the M socket is connected through the connecting means, the device that can be the bus master is put into the sleep state, and the program data is written from the ROM writer to the electrically rewritable ROM mounted on the printed circuit board. After mounting the ROM on the printed circuit board by soldering, there is an effect that the program data can be written in many ROMs on the printed circuit board at one time by using the ROM writer.

According to a second aspect of the present invention, in the first aspect, the connecting means is constituted by a board, and the board is electrically rewritable in a state of being mounted on the printed board. Since the external power supply used for writing to the ROM and the power supply voltage tracking supply unit that supplies the external power supply voltage to the interface unit of the printed circuit board by following the power supply voltage supplied from the ROM socket of the ROM writer, In addition to the effect similar to that of the first aspect, there is an effect that the ROM writer can cope with the case where the ROM writer has only the power supply capability to the ROM alone and the power consumption current of the printed circuit board is large.

According to a third aspect of the present invention, in the first or second aspect, the connecting means is composed of a substrate and is necessary for writing an electrically rewritable ROM on the substrate. Since the signal output from the ROM writer is provided to the interface section of the printed circuit board via the buffer section, the same effect as in claim 1 or 2 can be obtained. In addition to being obtained, the ROM writer has an effect of being able to cope with a case where the ROM writer only has a signal drive capability for a single ROM and a drive load for an input signal of the printed circuit board is large.

On the other hand, according to the fourth aspect of the present invention, the device which can be a bus master can be put into a sleep state from the outside on a printed circuit board on which a device which can be a bus master and a plurality of electrically rewritable ROMs are mounted. And an interface section capable of externally controlling the plurality of electrically rewritable ROMs, and the interface section and the R of the ROM writer.
The printed circuit board is equipped with a connecting means for connecting to the OM socket and a chip select switching means for switching and supplying a chip select signal from the ROM writer to each of a plurality of electrically rewritable ROMs. In which a plurality of rewritable ROMs are mounted, the interface section and the ROM socket of the ROM writer are connected via the connecting means, and the device which can be the bus master is put in the sleep state and mounted on the printed circuit board. R by using the chip select switching means for each of a plurality of electrically rewritable ROMs.
Since the program data is written from the OM writer, the same effect as in claim 1 can be obtained, and
Even if a plurality of ROMs are mounted on the printed circuit board, there is an effect that writing to these plurality of ROMs is possible.

According to a fifth aspect of the present invention, in the fourth aspect, the connecting means is formed of a board to mount the chip select switching means, and the printed board is mounted on the board. The external power supply used for writing a plurality of electrically rewritable ROMs in the closed state and the power supply voltage supplied from the ROM socket of the ROM writer, and supplies the external power supply voltage to the interface section of the printed circuit board. Since the power supply follow-up supply unit is provided, the same effect as in claim 4 can be obtained, and the ROM writer can only supply power to a single ROM, and can respond even when the power consumption of the printed circuit board is large. There is.

Further, according to the invention of claim 6, in claim 4 or 5, the connecting means is constituted by a substrate to mount the chip select switching means, and an electrical circuit is formed on the substrate. Is equipped with a buffer unit for signals necessary for writing a plurality of rewritable ROMs,
Since the signal output from the ROM writer is supplied to the interface section of the printed circuit board via the buffer section, the same effect as in claim 4 or 5 can be obtained, and the ROM writer is a single ROM It has the effect of being able to cope with the case where there is only a signal driving capability to the input circuit and the drive load for the input signal of the printed circuit board is large.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration in an embodiment of each invention of the present application.

FIG. 2 is a block diagram showing a configuration according to the invention of claims 1 to 3 in the printed circuit board of FIG.

FIG. 3 is a block diagram showing a configuration of a conversion board according to the embodiment of the invention described in claim 1.

FIG. 4 is a flowchart showing a flash ROM writing process by a ROM writer.

FIG. 5 is a block diagram showing a configuration of a conversion board according to an embodiment of the invention described in claim 2.

6 is a circuit diagram showing a configuration example of a power supply voltage tracking supply unit in FIG.

FIG. 7 is a circuit diagram showing another configuration example of the power supply voltage tracking supply unit of FIG.

FIG. 8 is a block diagram showing a configuration of a conversion board according to an embodiment of the invention as set forth in claim 3;

9 is a block diagram showing a configuration according to the invention of claims 4 to 6 in the printed circuit board of FIG.

FIG. 10 is a block diagram showing a configuration of a conversion board according to an embodiment of the invention described in claims 4 to 6;

11 is a circuit diagram showing a configuration example of a chip select switching unit in FIG.

12 is a circuit diagram showing another configuration example of the chip select switching unit in FIG.

[Explanation of symbols]

 1 Printed Circuit Board 2 Conversion Board 3 ROM Writer 11 CPU 12, 25 Flash ROM 13, 21, Flash ROM Control I / F 22 ROM Writer I / F 23 Power Supply Voltage Tracking Supply Section 23a DC Power Supply 23b Relay 23c Operational Amplifier 23d Transistor 24 Buffer Section 26 Chip select switching section

Claims (6)

[Claims] 1. A device that can be a bus master and a ROM that is electrically rewritable are mounted on a printed circuit board. The device that can be the bus master can be put into a sleep state from the outside, and the electrically rewritable ROM is externally mounted. An interface section that can be controlled from the interface board, and a connection means that connects the interface section and a ROM socket of a ROM writer, and the interface in a state where an electrically rewritable ROM is mounted on the printed circuit board. Section and the ROM socket of the ROM writer via the connection means, put the device that can be the bus master into a sleep state,
Electrically rewritable RO mounted on printed circuit board
An electrically rewritable ROM writing method, wherein program data is written to M from a ROM writer. 2. The connection means is composed of a board, and an external power source used for writing an electrically rewritable ROM mounted on the printed board on the board, and a ROM socket of the ROM writer. 2. The electrically rewritable ROM according to claim 1, further comprising a power supply voltage tracking supply unit that supplies the external power supply voltage to the interface unit of the printed circuit board by following the power supply voltage supplied from How to write. 3. The connection means is composed of a substrate, and a buffer portion for signals necessary for writing electrically rewritable ROM is provided on the substrate, and a signal output from the ROM writer is transmitted by the substrate. 3. The interface unit of the printed circuit board is supplied via a buffer unit.
5. The electrically rewritable ROM writing method according to any one of 1. 4. A plurality of electrically rewritable devices that can put the devices that can be bus masters into a sleep state from the outside on a printed circuit board on which a device that can be a bus master and a plurality of electrically rewritable ROMs are mounted. A ROM capable of controlling the ROM from the outside, a connecting means for connecting the interface section to the ROM socket of the ROM writer, and a plurality of ROMs capable of electrically rewriting the chip select signal from the ROM writer. A plurality of ROs that are electrically rewritable on the printed circuit board.
In the state where M is mounted, the interface section and the ROM socket of the ROM writer are connected through the connecting means, the device that can be the bus master is put in the sleep state, and the device is electrically rewritable mounted on the printed circuit board. An electrically rewritable RO characterized in that program data is written from a ROM writer to each of a plurality of ROMs by using the chip select switching means.
How to write M. 5. The connection means is composed of a board, the chip select switching means is mounted on the board, and a plurality of electrically rewritable ROMs mounted on the printed board are written on the board. An external power supply to be used, and a power supply voltage tracking supply unit for supplying the external power supply voltage to the interface unit of the printed circuit board by following the power supply voltage supplied from the ROM socket of the ROM writer. Item 4. An electrically rewritable ROM writing method according to Item 4. 6. The connection means is composed of a board, the chip select switching means is mounted, and a buffer section for signals necessary for writing a plurality of electrically rewritable ROMs is provided on the board. 6. The signal output from the ROM writer is supplied to the interface section of the printed circuit board via the buffer section.
5. The electrically rewritable ROM writing method according to any one of 1.