W79E825A Datasheet, PDF (20/127 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E825A/824A/823B/822B Data Sheet
PORT 0
Bit: 7
P0.7
6
P0.6
5
P0.5
4
P0.4
3
P0.3
2
P0.2
1
P0.1
0
P0.0
Mnemonic: P0
Address: 80h
P0.7-0: General purpose Input/Output port. Most instructions will read the port pins in case of a port
read access, however in case of read-modify-write instructions, the port latch is read. These alternate
functions are described below:
BIT NAME
FUNCTION
7 P0.7 Timer 1 pin or KBI.7 pin of keypad input.
6 P0.6 CMP1 pin of analog comparator or KBI.6 pin of keypad input.
5 P0.5 CMPREF pin of analog comparator or KBI.5 pin of keypad input.
4 P0.4 CIN1A pin of analog comparator or KBI.4 pin of keypad input.
3 P0.3 CIN1B pin of analog comparator or KBI.3 pin of keypad input.
2 P0.2 BRAKE pin of PWM or CIN2A pin of analog comparator or KBI.2 pin of keypad input.
1 P0.1 PWM0 pin or CIN2B pin of analog comparator or KBI.1 pin of keypad input.
0 P0.0 PWM3 pin or CMP2 pin of analog comparator or KBI.0 pin of keypad input.
Note: The initial value of the port is set by CONFIG1.PRHI bit. The default setting for CONFIG1.PRHI =1 which the alternative
function output is turned on upon reset. If CONFIG1.PRHI is set to 0, the user has to write a 1 to port SFR to turn on the
alternative function output.
STACK POINTER
Bit: 7
6
5
4
3
2
1
0
SP.7
SP.6
SP.5
SP.4
SP.3
SP.2
SP.1
SP.0
Mnemonic: SP
Address: 81h
BIT NAME
FUNCTION
7-0
SP.[7:0]
The Stack Pointer stores the Scratch-pad RAM address where the stack begins. In
other words it always points to the top of the stack.
DATA POINTER LOW
Bit: 7
6
5
4
3
2
1
DPL.7
DPL.6
DPL.5
DPL.4
DPL.3
DPL.2
DPL.1
Mnemonic: DPL
BIT NAME
FUNCTION
7-0 DPL.[7:0] This is the low byte of the standard 8052 16-bit data pointer.
0
DPL.0
Address: 82h
DATA POINTER HIGH
Bit: 7
6
DPH.7
DPH.6
Mnemonic: DPH
5
DPH.5
4
DPH.4
3
DPH.3
2
DPH.2
1
0
DPH.1
DPH.0
Address: 83h
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