Acer 390 Series, Service Manual

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Major Chips Description 2-77
2.5 M38813
2.5.1 Overview
The M38813M4-XXXHP is an 8-bit single-chip microcomputer created in a silicon gate CMOS
process. Built into this single-chip microcomputer are:
•
Serial l/O function (either clock synchronous or UART method selectable in software)
•
8-bit timers
•
8-bit Comparator
•
Double Bus interface
The M38813M4-XXXHP is designed as a dedicated microcomputer for Keyboard controller. The
reduced power dissipation of the CMOS process also makes this microcomputer extremely useful
for applications utilizing battery power.
2.5.2 Description
The functions of the M38813M4-XXXHP are outlined in Table1.1.1. In this manual, the suffix HP
indicates a 0.5mm-lead pitch QFP.
Table 2-9 M38813M4-XXXHP Functions
Parameter Function
Basic instructions 71
Instruction execution time
0.5
µ
s (shortest instruction, at 8MHz oscillation frequency)
Oscillation frequency 8MHz (max.)
Memory size ROM 16384 bytes of user area
RAM 512 bytes
Input/output ports P0-P4 8-bit X 5
P5 4-bit X 1
P6 2-bit X 1
Serial l/O Clock synchronous or asynchronous
Timers 8-bit prescaler x 2 and 8-bit timer x 3
Comparator 4-bit resolution x 8 channels
Bus interface Two 8-bit Master CPU bus interface
Key on wake up 8 inputs
Interrupts 8 external, 9 internal, 1 software
Clock generation circuit Built-in (connect to external ceramic resonator or quartz crystal oscillator)
Supply voltage
f(X
IN
)=8MHz
4.0 to 5.5V
f(X
IN
)=4MHz
2.7 to 5.5V
Power dissipation 40mW (at 8MHz oscillation frequency, typ.)
Input/output characteristics Input/output break-down voltage 5V