Control Board - Philips MC-D370/22 Service Manual

5-1

CONTROL BOARD

TABLE OF CONTENTS
IC Internal Block Diagram ..................................... 5-1to 5-4
Circuit Diagram ................................................................ 5-5
PCB Layout Top View ...................................................... 5-6
PCB Layout Bottom View ................................................ 5-7
Electrical Parts List .......................................................... 5-8
MICROCONTROLLER AMPLIFIER
EM78P156EL
FUNCTIONAL BLOCK DIAGRAM
OSCI OSCO /RESET
TCC
Oscillator/Timing
WDT Timer
Control
Prescaler
IOCA
WDT
Time-out
R1(TCC)
RAM
Sleep
& Wake
Control R4
IOC5
R5
P P P P
5 5 5 5
0 1 2 3
PIN DESCRIPTION
Symbol I/O
OSCI I * XTAL type : Crystal input terminal or external clock input pin.
* ERC type: RC oscillator input pin.
OSCO I/O * XTAL type: Output terminal for crystal oscillator or external clock input pin.
* ERC type: Instruction clock ouput.
* External clock signal input.
TCC I * Real time clock/counter with Schmitt trigger input pin, must be tied to V
or V
SS
/RESET I * Input pin with Schmitt trigger. If this pin remains at logic low, the controller
will keep in reset condition.
P50~P53 I/O * P50~P53 are bi-directional I/O pins. P50 and P51 can also be defined as the
R-option pins. P50~P52 can be pulled down by software .
P60~P67 I/O * P60~P67 are bi-directional I/O pins. These can be pull-high or can be open-
drain by software programming. In addition, P60~P63 can be pull-down
also by software.
/INT I * External interrupt pin triggered by falling edge.
V - * Power supply.
DD
V - * Ground.
SS
5-1
/INT
R2
Stack
ROM
ALU
Interrupt Instruction
Controller register
Instruction
R3
Decoder ACC
DATA & CONTROL BUS
IOC6
R6
P P P P P P P P
6 6 6 6 6 6 6 6
0 1 2 3 4 5 6 7
Function
if not in use.
DD