Service manual

CPU Assembly
3-4
3CPU Assembly
This discussion of the CPU assembly covers the following circuits:
•CPU
• System Gate Array
• Serial EEROM
• System Memory (DRAM)
•ROM
• Printer Gate Array/SRAM
• Analog/Digital Converter
• System Expansion Connector
The block diagram in Figure 3-2 shows these circuits and how they interconnect.
Figure 3-2 CPU Block Diagram
Keyboard
and
LED(s)
M177X3-2
Display
(PW 200)
Serial
EEROM
1K bit
ECG
Front
End
System
Oscillator
Intel
80960SA
CPU
System
Gate
Array
Real-Time
Crystal
Clock
Reset
Low Address/Date
DRAM
256K X 16
Row/Col Addr.
ROM 1
256K X16
High
Address
Data
Control
Low
ROM 2
256K X 16
Printer
Gate
Array
Analog/
Digital
Converter
VBATT
VPRINT
Therm
Printer
SRAM
Thermal Printhead
Motor
Driver
Motor
Expansion
Connector
Address
Data
Control
ROM 1,2
(2) 512K x 16
or
(1) 2MB x 16
Based on Serial #