JPS63196931A - Self-diagnosing system for printer device - Google Patents

Abstract

PURPOSE:To switch a chip select signal in a printer device and to fulfill each function by providing a circuit for access switching of a memory card where a diagnostic program is stored. CONSTITUTION:When a memory card 20 is used as a normal external extended memory card, print font, print character data, or the like is stored in a ROM 22. Since connection information patterns are eliminated, a chip select signal CE0 for access of an internal firmware ROM 21 is validated by a switching circuit 24 and is applied to the ROM 21. Similarly, a chip select signal CE1 for access of an external memory is applied to the ROM 22 in the external memory card by switching circuits 25 and 26 and an OR circuit 27 and the ROM 22 is selected. Consequently, the chip select signal is switched between setting of the external extended memory and setting of a self-diagnosing memory card and respective functions are fulfilled.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a self-diagnosis method for the functions of a printer device.
? This paper relates to a self-diagnosis execution method using embedded software.

[Conventional technology]

Conventionally, methods for executing self-diagnosis of printer devices include device built-in software (hereinafter abbreviated as F/W),
The self-diagnosis program is resident in a storage area and executed by an operator's operation or by loading the diagnostic program from a host device.

[Problem that the invention seeks to solve]

In the conventional printer self-diagnosis method described above, in the former method, the self-diagnosis program resides in the area of the embedded software, so there is a limit to the number of program steps, and in order to perform detailed diagnosis of the memory area, etc. In addition, it is necessary to add more memory for embedded software.
The latter method requires a host device to perform self-diagnosis, and the control circuit on the printer side is also complicated.

[Means for solving problems]

The self-diagnosis method of the printer device of the present invention is such that when a memory card storing a self-diagnosis program is inserted into the insertion mechanism section of an external expansion memory, the built-in software of the printer device is inserted into the memory card storing the diagnostic program. It has a circuit for switching access to.

〔Example〕

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, and FIG. 2 is a circuit block diagram when the method according to the present invention is used for mounting a conventional external memory.

In FIG. 1, 10 is a memory card storing a self-diagnosis program, and 11 is an F/WROM of the printer device.
It is connected to the internal address bus and data bus. Reference numeral 12 is a ROM storing a self-diagnosis program, and 13 is a connection information pattern for the self-diagnosis memory card, which transmits a GND signal to the device side when the memory card is connected. 14 is a circuit for switching the chip selection signal CEO for accessing ROMII, 15.16 is a circuit for RO
Chip selection signals CEO and CE for accessing M12
17 is an OR circuit.

When the memory card 10 storing the self-diagnosis F/W whose operation will be explained with reference to FIG. 1 is installed, the GND level is applied to the device side circuit according to the connection information pattern 13. Due to this, the chip selection signal CEO for accessing the internal F/W ROMI 1 is switched to the switching circuit 14.15.
is applied to ROM12 in the external memory card, and the RO
M12 is selected. At this time, the ROM in the external memory card
Chip selection signal CEI for access is switch port w116
It is invalidated due to

Next, a case where the card is used as a normal external expansion memory card will be explained with reference to FIG. This is a memory card that stores external expansion memories from 20 companies, and the ROM 22 stores printing fonts, printing character data, etc. Other components are the same as those in FIG. 1, except for the connection information pattern 13. Since there is no connection information pattern, the chip selection signal CEO for accessing the internal F/W ROM 21 is applied to the ROM 21 (validated by the switching circuit 24), and similarly, the chip selection signal CEO for accessing the internal F/W ROM 21 is applied to the ROM 21.
OM22- is selected by being applied to the chip selection signal CEI for external memory access by the switching circuits 25, 26 and the OR circuit M27.

As explained above, the chip selection signal within the printer device is switched between when the external expansion memory shown in Figure 2 is installed and when the self-diagnosis memory card shown in Figure 1 is installed, and the respective functions are changed. can demonstrate.

〔Effect of the invention〕

As explained above, the present invention has a circuit for switching access to the internal F/W ROM when a memory card storing self-diagnosis F/W is installed in the external expansion memory storage mechanism of the printer device. In addition, it is possible to separate and store a program for self-diagnosis of the internal circuit of the printer device, especially for diagnosing the printer device, etc.)
Compared to the program resident method, there are no capacity constraints, and there is no need to perform operations such as loading programs from the host device, making it possible to perform self-diagnosis with the same operations as when installing regular external memory. be.

[Brief explanation of the drawing]

1 and 2 are circuit block diagrams showing one embodiment of the present invention. 10...Memory card storing self-diagnosis program, 11.21...7 Armware (F/W) ROM of printer device, 12...Self-diagnosis program storage ROM, 22... External expansion memo! JROM113...Connection information pattern,
14,15.24.25...CEO switching circuit,
16.26...CEI switching circuit, 17.27.
...OR circuit, CEO...Internal F/WR
OM selection signal, CEI...External memory selection signal. Agent: Susumu Uchihara, Patent Attorney, 11-〆

Claims (1)

[Claims] When a memory card containing a self-diagnosis program is installed in the external expansion memory or storage mechanism of the printer device,
A self-diagnosis method for a printer device, characterized in that access is switched to a memory card storing the diagnostic program instead of the device's built-in software.