w78c32c Winbond Electronics Corp America, w78c32c Datasheet - Page 4

• Manufacturer Part Number: w78c32c
• Description: 8-bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

Program Store Enable Output, active low. PSEN enables the external ROM onto the Port 0
address/data bus during fetch and MOVC operations. PSEN goes to a high state during reset with a
weak pull-up.
XTAL1
Crystal 1. This is the crystal oscillator input. This pin may be driven by an external clock.
XTAL2
Crystal 2. This is the crystal oscillator output. It is the inversion of XTAL1.
V
Power Supplies. These are the chip ground and positive supplies.
BLOCK DIAGRAM
PSEN
SS
, V
CC
Bytes
RAM
256
CORE
CPU
- 4 -
Data Bus
Interrupt
SFR
Timer 2
Timer 1
Timer 0
Serial
INT 0
INT 1
Port
Alternate
Alternate
Port 1
Port 0
Port 2
Port 3
W78C32C