Intel 8XC251SP User Manual

4-11

DEVICE CONFIGURATION

Figure 4-6. Internal/External Address Mapping (RD1:0 = 10 and 11)

FF:

01:

PSEN#

RD#, WR#

A4217-02

FF:

FE:

01:

00:

RD1:0 = 10

16 external address bits:
P0, P2

PSEN#, WR#

FE:, FF:

00:, 01:

00:, 01:, FE:, FF:

64 Kbytes

128 Kbytes

Notes:
1. Single read signal
2. P3.7/RD#/A16 functions
only as P3.7

Note:
1. Compatible with MCS

microcontrollers
2. Cannot write to regions FC:–FF:

Internal Memory with

Read/Write Signals

External
Memory

RD1:0 = 11

Internal Memory with

Read/Write Signals

External
Memory

16 external address bits:
P0, P2

FE:

00: