Datasheet

#$
#$
#$$
SBAS317E − APRIL 2004 − REVISED MAY 2006
www.ti.com
47
Stack Pointer (SP)
7 6 5 4 3 2 1 0 Reset Value
SFR 81h SP.7 SP.6 SP.5 SP.4 SP.3 SP.2 SP.1 SP.0 07h
SP.7−0 Stack Pointer. The stack pointer identifies the location where the stack will begin. The stack pointer is incremented before
bits 7−0 every PUSH or CALL operation and decremented after each POP or RET/RETI. This register defaults to 07h after reset.
Data Pointer Low 0 (DPL0)
7 6 5 4 3 2 1 0 Reset Value
SFR 82h DPL0.7 DPL0.6 DPL0.5 DPL0.4 DPL0.3 DPL0.2 DPL0.1 DPL0.0 00h
DPL0.7−0 Data Pointer Low 0. This register is the low byte of the standard 8051 16-bit data pointer. DPL0 and DPH0 are used
bits 7−0 to point to non-scratchpad data RAM. The current data pointer is selected by DPS (SFR 86h).
Data Pointer High 0 (DPH0)
7 6 5 4 3 2 1 0 Reset Value
SFR 83h DPH0.7 DPH0.6 DPH0.5 DPH0.4 DPH0.3 DPH0.2 DPH0.1 DPH0.0 00h
DPH0.7−0 Data Pointer High 0. This register is the high byte of the standard 8051 16-bit data pointer. DPL0 and DPH0 are used
bits 7−0 to point to non-scratchpad data RAM. The current data pointer is selected by DPS (SFR 86h).
Data Pointer Low 1 (DPL1)
7 6 5 4 3 2 1 0 Reset Value
SFR 84h DPL1.7 DPL1.6 DPL1.5 DPL1.4 DPL1.3 DPL1.2 DPL1.1 DPL1.0 00h
DPL1.7−0 Data Pointer Low 1. This register is the low byte of the auxiliary 16-bit data pointer. When the SEL bit (DPS.0)
bits 7−0 (SFR 86h) is set, DPL1 and DPH1 are used in place of DPL0 and DPH0 during DPTR operations.
Data Pointer High 1 (DPH1)
7 6 5 4 3 2 1 0 Reset Value
SFR 85h DPH1.7 DPH1.6 DPH1.5 DPH1.4 DPH1.3 DPH1.2 DPH1.1 DPH1.0 00h
DPH1.7−0 Data Pointer High. This register is the high byte of the auxiliary 16-bit data pointer. When the SEL bit (DPS.0)
bits 7−0 (SFR 86h) is set, DPL1 and DPH1 are used in place of DPL0 and DPH0 during DPTR operations.
Data Pointer Select (DPS)
7 6 5 4 3 2 1 0 Reset Value
SFR 86h 0 0 0 0 0 0 0 SEL 00h
SEL Data Pointer Select. This bit selects the active data pointer.
bit 0 0: Instructions that use the DPTR will use DPL0 and DPH0.
1: Instructions that use the DPTR will use DPL1 and DPH1.