W78C438C

Publication Release Date: July 1998

- 5 -

Revision A1

P8.0

−P8.7 I/O Port

Functions are the same as those of Port 1 in the W78C31, except that they are mapped by the P8

register and not bit-addressable. The P8 register is not a standard register in the W78C32. Its address

is at 0A6H.

INT2

of these interrupts are determined/shown by the bits in the XICON (External Interrupt Control)

register. The XICON register is bit-addressable but is not a standard register in the W78C32. Its

address is at 0C0H. For details, see the Functional Description below.

EA

External Address, Input

Functions same as W78C32.

Functions same as W78C32.

BLOCK DIAGRAM

SFR

RAM

256

Bytes

CPU

Serial

Port

Data Bus

CORE

Interrupt

INT0

Timer0

Timer2

Port 0

Port 1

Port 2

Alternate

Port 8

DP4

AP5

AP6

AP7

Alternate

INT1

Timer1

INT2

INT3

Port 3

Alternate