W77C58 Datasheet, PDF (9/71 Pages) Winbond – 8 BIT MICROCONTROLLER

Preliminary W77C58
Stack Pointer
Bit:
Mnemonic: SP
7
SP.7
6
SP.6
5
SP.5
4
SP.4
3
SP.3
2
1
0
SP.2 SP.1 SP.0
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:
Mnemonic: DPL
7
DPL.7
6
DPL.6
5
DPL.5
4
DPL.4
3
DPL.3
2
1
0
DPL.2 DPL.1 DPL.0
Address: 82h
This is the low byte of the standard 8052 16-bit data pointer.
Data Pointer High
Bit:
7
DPH.7
6
DPH.6
5
DPH.5
4
DPH.4
3
DPH.3
2
DPH.2
1
DPH.1
0
DPH.0
Mnemonic: DPH
This is the high byte of the standard 8052 16-bit data pointer.
Address: 83h
Data Pointer Low1
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
This is the low byte of the new additional 16-bit data pointer that has been added to the W77C58. The
user can switch between DPL, DPH and DPL1, DPH1 simply by setting register DPS = 1. The
instructions that use DPTR will now access DPL1 and DPH1 in place of DPL and DPH. If they are not
required the user can use them as conventional register locations.
Data Pointer High1
Bit:
7
6
5
4
3
2
1
0
DPH1.7 DPH1.6 DPH1.5 DPH1.4 DPH1.3 DPH1.2 DPH1.1 DPH1.0
Mnemonic: DPH1
Address: 85h
This is the high byte of the new additional 16-bit data pointer that has been added to the W77C58.
The user can switch between DPL, DPH and DPL1, DPH1 simply by setting register DPS = 1. The
Publication Release Date: September 1999
-9-
Revision A1