W77IE58
- 12 -
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 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 W77IE58. 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 they can be used as conventional register locations by the user.
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 W77IE58.
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 they can be used as conventional register locations by the user.
Data Pointer Select
Bit: 7 6 5 4 3 2 1 0
- - - - - - - DPS.0
Mnemonic: DPS Address: 86h
DPS.0: This bit is used to select either the DPL, DPH pair or the DPL1, DPH1 pair as the active Data
Pointer. When set to 1, DPL1, DPH1 will be selected, otherwise DPL, DPH will be selected.
DPS.1-7: These bits are reserved, but will read 0.
