Rainbow Electronics AT89C5131 - Manual (Page 14)

14
AT89C5131
4136A–USB–03/03
The Special Function Registers (SFRs) of the AT89C5131 fall into the following
categories:
Table 13. C51 Core SFRs
Table 14. I/O Port SFRs
Mnemonic Add Name 7 6 5 4 3 2 1 0
ACC E0h Accumulator
B F0h B Register
PSW D0h
Program Status
Word
SP 81h
Stack Pointer
LSB of SPX
DPL 82h
Data Pointer
Low byte
LSB of DPTR
DPH 83h
Data Pointer
High byte
MSB of DPTR
Mnemonic Add Name 7 6 5 4 3 2 1 0
P0 80h Port 0
P1 90h Port 1
P2 A0h Port 2
P3 B0h Port 3
P4 C0h Port 4 (x2)