Preliminary W928C73
Publication Release Date: June 2000
- 15 - Revision A1
Descriptions Of Special Function Registers (SFRS), continued
ADDRESS
/NAME
BIT
BIT NAME
R/W
1
0
INITIAL
FUNCTION
DAH/P1IO
B7~0
P1IO
W
00000000 Bit addressable R/W control for P1:
1: input mode without pull high R
0: output mode or input with pull high R
Set DA to “00000000 “ after reset, since P1
are all output mode.
DBH/P2IO
B7~0
P2IO
W
00000000 Bit addressable R/W control for P2
1: input mode without pull high R
0: output mode or input with pull high R
Set DB to “X0000000 “ after reset.
The value of P2IO.7 depends on the function
of P2.7 (input of output)
DCH/P3IO
B7~0
P3IO
W
00000000 Bit addressable R/W control for P3
1: input mode without pull high R
0: output mode or input with pull high R
Set DC to “10001XXX “ after reset.
The values of P3IO.2~P3IO.0 depend on the
functions of P3.2~P3.0 (input of output)
DDH/P48IO
B4
P8IO
W
0
B3
P7IO
W
0
B2
P6IO
W
0
B1
P5IO
W
0
B0
P4IO
W
0
Clear DDH to “00” after reset.
E0H/ACC
B7~0
ACC R/W
00000000 Accumulator
E8H/EIE
B7
ERTLC
W
Enable
Disable
0
RTC timer and LCD clock enable
B6
EBTI
W
Enable
Disable
0
Buzzer timer interrupt enable
B5
ERTI
W
Enable
Disable
0
RTC timer interrupt enable
B4
EWDI
W
Enable
Disable
0
Watchdog timer interrupt enable
B3
IE3
R
0
External interrupt 3 request flag
B2
EX3
W
Enable
Disable
0
External interrupt 3 enable
B1
IE2
R
0
External interrupt 2 request flag
B0
EX2
W
Enable
Disable
0
External interrupt 2 enable
F0/B
B7~0
B R/W
00000000 B register
F8H/EIP
B7
SMSC
W
H_clock L_clock
0
System clock selection
B6
PBTI
W
High
Low
0
Buzzer timer interrupt priority
B5
PRTI
W
High
Low
0
RTC timer interrupt priority
B4
PWDI
W
High
Low
0
Watchdog timer interrupt priority
B3
IT3
W
Falling
Rising
0
INT3 (key_INT) trigger edge selection
B2
PX3
W
High
Low
0
External interrupt 3 priority
B1
IT2
W
Falling
Rising
0
INT2 (ADDT) trigger edge selection
B0
PX2
W
High
Low
0
External interrupt 2 priority
Notes:
1. The SFRs in bold are bit addressable, others are byte addressable.
2. The SFRs can only be accessed by direct addressing.
3. P2.4 is pulled high internal, when external use V
DD
to connect p2.4 for LCD. The S/W must do the following instruction mov
P2IO,#10H and clr P2.4
4. P0IO~P8IO default are output mode(0), when need input mode then set P0IO~P8IO are 1.