Table 6-2. The Standard 80C51 SFRs
BIT ADDRESS & SYMBOL
RESET
VALUE
SYMBOL
DESCRIPTION
Accumulator
ADDR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
E7H
ACC.7
F7H
B.7
D7H
CY
E6H
ACC.6
F6H
B.6
D6H
AC
E5H
ACC.5
F5H
B.5
E4H
ACC.4
F4H
E3H
ACC.3
F3H
E2H
ACC.2
F2H
B.2
E1H
ACC.1
F1H
B.1
D1H
-
E0H
ACC.0
F0H
B.0
D0H
P
E0H
F0H
D0H
00H
00H
00H
ACC*
B*
B Register
B.4
B.3
D5H
F0
D4H
RS1
D3H
RS0
D2H
OV
Program Status Word
PSW*
SP
Stack Pointer
81H
83H
82H
07H
00H
00H
DPH
DPL
Data Pointer High
Data Pointer Low
87H
P0.7
97H
P1.7
A7H
P2.7
B7H
P3.7
BFH
-
86H
P0.6
96H
P1.6
A6H
P2.6
B6H
P3.6
BEH
-
85H
P0.5
95H
P1.5
A5H
P2.5
B5H
P3.5
BDH
PT2
ADH
ET2
84H
P0.4
94H
P1.4
A4H
P2.4
B4H
P3.4
BCH
PS
83H
P0.3
93H
P1.3
A3H
P2.3
B3H
P3.3
BBH
PT1
ABH
ET1
82H
P0.2
92H
P1.2
A2H
P2.2
B2H
P3.2
BAH
PX1
AAH
EX1
81H
P0.1
91H
P1.1
A1H
P2.1
B1H
P3.1
B9H
PT0
A9H
ET0
80H
P0.0
90H
P1.0
A0H
P2.0
B0H
P3.0
B8H
PX0
A8H
EX0
Port 0
80H
90H
A0H
B0H
B8H
FFH
FFH
FFH
FFH
00H
P0*
P1*
P2*
P3*
IP*
Port 1
Port 2
Port 3
Interrupt Priority
Interrupt Enable
AFH
EA
AEH
-
ACH
ES
A8H
89H
88H
00H
00H
00H
IE*
TMOD Timer Mode
GATE
C/-T
M1
M0
GATE
C/-T
M1
M0
8FH
TF1
CFH
TF2
8EH
TR1
CEH
EXF2
8DH
TF0
CDH
RCLK
8CH
TR0
CCH
TCLK
8BH
IE1
CBH
8AH
IT1
CAH
TR2
89H
IE0
C9H
88H
IT0
C8H
Timer Control
TCON*
Timer 2 Control
T2CON*
C8H
00H
EXEN2
C/-T2 CP/-RL2
TH0
TL0
TH1
TL1
TH2
TL2
Timer 0, High-byte
Timer 0, Low-byte
Timer 1, High-byte
Timer 1, Low-byte
Timer 2, High-byte
Timer 2, Low-byte
8CH
8AH
8DH
8BH
CDH
CCH
CBH
CAH
00H
00H
00H
00H
00H
00H
00H
00H
RCAP2H Timer 2 Capture, High
RCAP2L Timer 2 Capture, Low
9FH
SM0/FE
9EH
SM1
9DH
SM2
9CH
REN
9BH
TB8
9AH
RB8
99H
TI
98H
RI
Serial Port Control
SCON*
98H
00H
xxH
SBUF
Serial Data Buffer
99H
87H
#
PCON Power Control
SMOD SMOD0
-
POF
GF1
GF0
PD
IDL
10H
Notes:
*: Bit addressable
-: Reserved bit
#: Reset value depends on reset source.
MEGAWIN
MPC82G516A Data Sheet
26
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
