By:
Masud-ul-Hasan
19
External Bus
Expansion
8051
PORT 2
PORT 0
ALE
P3.7
P3.6
PSEN
A15
- A8: High byte of address
AD7 - AD0: Data and low
byte
address
ALE: Address latch enable
RD: Read strobe
WR: Write strobe
PSEN: Program store
enable
EA
