Light Therapy Device User Manual

Philips Semiconductors
User’s Manual - Preliminary -
P89LPC901/902/903
GENERAL DESCRIPTION
2003 Dec 8 11
Block Diagram - P89LPC903
Port 0
Configurable I/Os
128 byte
Data RAM
1KB Code
Flash
Internal Bus
Timer0
Timer1
Keypad
Interrupt
Power Monitor
(Power-On Reset,
Brownout Reset)
On-Chip
RC
Oscillator
Programmable
Oscillator Divider
CPU
Clock
Port 1
Input
Watchdog Timer
and Oscillator
UART
Analog
Comparators
Real-Time Clock/
System Timer
High Performance
Accelerated 2-clock
80C51 CPU