W77E058A Datasheet, PDF (12/87 Pages) Winbond – 8-BIT MICROCONTROLLER

W77E058A
A brief description of the SFRs now follows.
Port 0
Bit:
7
6
5
4
3
2
1
0
P0.7 P0.6 P0.5 P0.4 P0.3 P0.2 P0.1 P0.0
Mnemonic: P0
Address: 80h
Port 0 is an open-drain bi-directional I/O port. This port also provides a multiplexed low order
address/data bus during accesses to external memory.
Stack Pointer
Bit:
7
SP.7
6
SP.6
5
SP.5
4
SP.4
3
SP.3
2
SP.2
1
SP.1
0
SP.0
Mnemonic: SP
Address: 81h
The Stack Pointer stores the Scratchpad 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
0
DPL.7 DPL.6 DPL.5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0
Mnemonic: DPL
Address: 82h
This is the low byte of the standard 8052 16-bit data pointer.
Data Pointer High
Bit:
7
6
5
4
3
2
1
0
DPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0
Mnemonic: DPH
Address: 83h
This is the high byte of the standard 8052 16-bit data pointer.
Data Pointer Low 1
Bit:
7
6
5
4
3
2
1
0
DPL1.7 DPL1.6 DPL1.5 DPL1.4 DPL1.3 DPL1.2 DPL1.1 DPL1.0
Mnemonic: DPL1
Address: 84h
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