Maxim Integrated High-Speed Microcontroller Users Guide: DS80C390 Supplement - Manual (Page 16)

High-Speed Microcontroller User’s Guide: DS80C390 Supplement
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DATA POINTER HIGH 1 (DPH1)
7 6 5 4 3 2 1 0
SFR 85h DPH1.7 DPH1.6 DPH1.5 DPH1.4 DPH1.3 DPH1.2 DPH1.1 DPH1.0
RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-0
R = Unrestricted Read, W = Unrestricted Write, -n = Value after Reset
DPH1.7-0
Bits 7-0 Data Pointer High 1. This register is the high byte of the auxiliary 16-bit data
pointer. When the SEL bit (DPS.0) is set, DPL1 and DPH1 are used in place of
DPL and DPH during DPTR operations.
DATA POINTER SELECT (DPS)
7 6 5 4 3 2 1 0
SFR 86h ID1 ID0 TSL 0 0 1 0 SEL
RW-0 RW-0 RW-0 R-0 R-0 R-1 R-0 RW-0
R = Unrestricted Read, W = Unrestricted Write, -n = Value after Reset
ID1, ID0
Bits 7-6 Increment/Decrement Function Select . These bits define whether the INC
DTPR instruction will increment or decrement the active data pointer as selected
by the SEL bit.
ID1 ID0 SEL = 0 SEL = 1
0 0 Increment DPTR Increment DPTR1
0 1 Decrement DPTR Increment DPTR1
1 0 Increment DPTR Decrement DPTR1
1 1 Decrement DPTR Decrement DPTR1
TSL
Bit 5 Toggle Select Enable . When set, this bit allows the following five DPTR-
related instructions to toggle the SEL bit following execution of the
instruction. When TSL = 0, DPTR-related instructions will not affect the
state of the SEL bit. DPTR-related instructions are:
INC DPTR
MOV DPTR, #data16/#data22
MOVC A, @A+DPTR
MOVX @DPTR, A
MOVX A, @DPTR
Bits 4–1 Reserved
SEL
Bit 0 Data Pointer Select. This bit selects the active data pointer.
0 = Instructions that use the DPTR will use DPL, DPH, DPX.
1= Instructions that use the DPTR will use DPL1 and DPH1, DPX1.