4.4. Main Control Board

4.4.1. Main Control CPU

This CPU is an 8-bit microcontroller which is compatible with the Intel 80C51.
It contains the two types of memory: ROM : 4k bytes, RAM : 128 bytes
The CPU controls the RIP block of this printer. The main functions are as follows :
1) Initialization and control of GDI ASIC
2) Control the interface ( USB/Parallel ) port
3) Windows PnP ( Plug & Play ) detection in Parallel
4) LED Control and Key Detection on the front panel
The CPU processes the print data from the host PC through the GDI ASIC ( IC3 ).
Peripheral I/F
a) USB/Parallel Select
1284SEL toIC6 ( ASIC )
H : Parallel I/F port, L : USB I/F port
b) Front Panel I/F
nRDYLED sentto IC6 for driving READY LED on the front panel
nERRLED sentto IC6 for driving ERROR LED on the front panel
nDRMLED sent to IC6 for driving Process Unit LED on the front panel
nKEY front panel key signal for detecting the Key on the front panel
c) Interrupt
nINTR interrupt signal from IC3 ( ASIC )
nCAUTOFD signal from host PC in case of Windows’ PnP request
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KX-P7100