3. Electricai Overview
The information in this section appears in a sequence relative to the system diagram in the following figure.
SRAM
8bit
MPU
Driver
Head
ASIC
Driver
Carriage Motor
TO FAX PWB Host Interface
Driver
Feed Motor
Sensor
•Home Position
Figure 2 System of printer Block diagram
4. Power Supply Connector
The mechanism requires two voltages (+5V and +24V).
These two voltages supplied from CNPRT connector.
5. Host interface connector
Connector CNPRT on the printer PWB provides 28 lines from the host unit, for control of various operating options available to the host.
The two primary functions of the host interface are: Printing data for the Ink Jet Printer.
Error status to the host.
6. ASIC, RAM, and CPU
The Application Specific Integrated Circuit(ASIC) combines several blocks of circuitry into one chip. Descriptions of circuitry within the ASIC appear later in the section.
A microprocessor bus, which extends inside the ASIC, carries data among the CPU(include internal ROM), RAM, and ASIC circuitry.
The ROM (inside CPU) is a 8K Byte chip that contains the software code (firmware) for the Ink Jet Printer. The RAM is a 32 K Byte chip that stores print data and other variable information.
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