
5
AT89C51RB2/RC2
4180E–8051–10/06
Table 2. C51 Core SFRs
Mnemonic
Add
Name
76543210
ACC
E0h
Accumulator
B
F0h
B Register
PSW
D0h
Program Status Word
CY
AC
F0
RS1
RS0
OV
F1
P
SP
81h
Stack Pointer
DPL
82h
Data Pointer Low Byte
DPH
83h
Data Pointer High Byte
Table 3. System Management SFRs
Mnemonic
Add
Name
76543210
PCON
87h
Power Control
SMOD1
SMOD0
-
POF
GF1
GF0
PD
IDL
AUXR
8Eh
Auxiliary Register 0
DPU
-
M0
XRS2
XRS1
XRS0
EXTRAM
AO
AUXR1
A2h
Auxiliary Register 1
-
ENBOOT
-
GF3
0
-
DPS
CKRL
97h
Clock Reload Register
CKRL7
CKRL6
CKRL5
CKRL4
CKRL3
CKRL2
CKRL1
CKRL0
CKCKON0
8Fh
Clock Control Register 0
-
WDTX2
PCAX2
SIX2
T2X2
T1X2
T0X2
X2
CKCKON1
AFh
Clock Control Register 1
-------
SPIX2
Table 4. Interrupt SFRs
Mnemonic
Add
Name
76543210
IEN0
A8h
Interrupt Enable Control 0
EA
EC
ET2
ES
ET1
EX1
ET0
EX0
IEN1
B1h
Interrupt Enable Control 1
-----
ESPI
EI2C
KBD
IPH0
B7h
Interrupt Priority Control High 0
-
PPCH
PT2H
PHS
PT1H
PX1H
PT0H
PX0H
IPL0
B8h
Interrupt Priority Control Low 0
-
PPCL
PT2L
PLS
PT1L
PX1L
PT0L
PX0L
IPH1
B3h
Interrupt Priority Control High 1
-----
SPIH
IE2CH
KBDH
IPL1
B2h
Interrupt Priority Control Low 1
-----
SPIL
IE2CL
KBDL
Table 5. Port SFRs
Mnemonic
Add
Name
76543210
P0
80h
8-bit Port 0
P1
90h
8-bit Port 1
P2
A0h
8-bit Port 2
P3
B0h
8-bit Port 3