JPH01165469A - Function diagnosis for printer device - Google Patents

Abstract

PURPOSE:To diagnose the functions of a large capacity memory at high speed, by providing an internal ROM, a buffer circuit by which a signal for access to the internal ROM in a printer device is brought into a floating condition, and a connecting mechanism part having an input terminal for externally controlling the buffer circuit and functioning for fetching data from the internal ROM to the exterior. CONSTITUTION:A bus buffer control signal CNT is not applied from an external connecting mechanism part 6, so that bus buffer circuits 1,2 operate as buffers, whereby an address bus signal AB and an enable signal EN are transmitted from a CPU to a memory, while a data bus signal DB is transmitted from the memory to the CPU. The CPU reads data from internal ROMs 3-5 according to an ordinary memory map. At the time of diagnosing the functions of the internal ROMs 3-5, an external diagnosing device is connected to the external connecting mechanism part 6, a control signal is applied to the bus buffer control signal CNT to bring the output side of the bus buffer circuits 1, 2 into a floating condition, thereby enabling address signals A0-An, timing signals CLK0-CLKi and data bus signals D0-Dm to be externally controlled, and data are read from the internal ROMs 3-5.

Description

[Detailed description of the invention] [Industrial application field] Concerning equipment function diagnosis method.

[Conventional technology]

In the conventional printer function diagnosis method, when diagnosing information related to built-in characters, symbols, and kanji, a self-diagnosis program is resident in the printer's built-in software (hereinafter abbreviated as F/W) storage area. Internal CPT
The method used was to read out the information one by one using J, calculate it according to a predetermined procedure such as addition, and judge whether the contents were good or bad.

[Problem that the invention seeks to solve]

However, in the conventional printer function diagnosis method described above, when diagnosing the built-in large-capacity memory, the memory access method is performed by the internal CPU, so reading is performed at the speed of command execution by the F/W. Therefore, there is a drawback that the more character information, font information, etc. that are built into the printer, the more time is required for diagnosis.

[Means for solving problems]

The printer function diagnosis method of the present invention includes a buffer circuit that floats a signal for accessing the memory of the internal circuit of the printer, an input terminal for externally controlling the external buffer circuit, and information from the memory. It is configured with a connection mechanism for taking it out to the outside.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit block diagram showing one embodiment of the present invention.

A path buffer circuit 1 for floating the signal transmitted to the internal CPU, and a path buffer circuit 2 for floating the signal transmitted to the internal CPU.
In the built-in ROM printer device, characters, symbols,
It is configured to include built-in ROMs 3, 4.5, which are memories for storing information such as fonts, and a connecting mechanism section 6 for connecting the internal circuit of the printer device and the external circuit.

Address signals AO to A are used as contact signals with external circuits.
It has various timing signals CLKO to CLKi, bus buffer control signals CNT, and data signals Do to Dn. The address bus signal AB is supplied to an address bus directly connected to the printer's internal CPU, and the enable signal EN
is a signal from the CPU necessary for reading from the memory, and the data bus signal DB is supplied to a data bus directly connected to the CPU.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

In the normal operating state of the printer device, the pass buffer control signal CNT is not applied from the external connection mechanism section 6, so the pass buffer circuit 1-2 operates as a buffer, and the address bus signal AB and enable signal EN are
The data bus signal DB reads the CPU direction information from the memory according to the normal memory map. , by applying a control signal to the pass buffer control signal CNT and setting the output sides of the pass buffer circuits 1 and 2 in a floating state, the address signals AO-A n 1 and various timing signals CLKO to U are generated.

〔Effect of the invention〕

The printer function diagnosis method of the present invention includes a buffer circuit for floating a signal for accessing the memory of the internal circuit of the printer, and a signal input terminal for controlling this buffer circuit from the outside. By supplying all the signals for accessing the memory from an external diagnostic device and having a circuit configuration that can import the data into the external diagnostic device, it is possible to store character and font information implemented in the printer device. large capacity mail
Functional diagnosis can be performed at high speed by increasing the operating speed of the internal circuit's CPU, and AC parametric testing, which is a characteristic of the device, and DC parametric testing in parallel can be performed, increasing the reliability of functional diagnosis. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention. Bus signal, EN...Enable signal, DB・
...Data bus signal, AO - An ...Address signal, CLKO - CLKi ...Timing signal, C - T ...Pass buffer control signal, D
O~Dm...Data signal. Agent Patent Attorney Oto Uchihara

Claims (1)

[Claims] a buffer circuit that floats a signal for accessing the built-in ROM and the built-in ROM of the printer device; and a connection mechanism that has an input terminal for controlling the buffer circuit from the outside and takes out information from the built-in ROM to the outside. A method for diagnosing functions of a printer device, comprising: