Maxim Integrated High-Speed Microcontroller Users Guide: Network Microcontroller Supplement - Manual (Page 26)

High-Speed Microcontroller User’s
Guide: Network Microcontroller
Supplement
26
Data Pointer Select (DPS)
ID1, ID0
Bits 7–6
TSL
Bit 5
AID
Bit 4
Reserved
Bits 2, 1
SEL1, SEL
Bits 3, 0
Increment/decrement function select. These bits define whether the INC DTPR instruction 7-6 incre-
ments or decrements the active data pointer when DPTR1 or DPTR are selected by the SEL1, SEL bits.
ID1 ID0 SEL1, SEL = 00 SEL1, SEL = 01
0 0 Increment DPTR Increment DPTR1
0 1 Decrement DPTR Increment DPTR1
1 0 Increment DPTR Decrement DPTR1
1 1 Decrement DPTR Decrement DPTR1
Toggle select enable. When set, this bit allows the following five DPTR-related instructions to toggle the
SEL bit, followingexecution of the instruction. When TSL = 0, DPTR-related instructions do not affect the
state of the SEL bit. DPTR-related instructions are:
INC DPTRz
MOV DPTR, #data16
MOVC A, @A+DPTR
MOVX @DPTR, A
MOVX A, @DPTR
Automatic increment/decrement enable. This bit allows three of the DPTR-related instructions to incre-
ment (or decrement) the content of the active DPTR, if enabled. The actual function (increment or decre-
ment) is dependent on the setting of the ID3, ID2, ID1, and ID0 bits. The active data pointer is incre-
mented (or decremented) by 1 after execution of DPTR-related instruction when AID bit is set to logic 1.
When AID is cleared to 0, a DPTR-related instruction does not affect the content of the active DPTR.
This option is affected by the following instructions:
MOVC A, @A+SPTR
MOVX @SPTR, A
MOVX A, @DPTR
Reserved. (Returns 10b when read.) These bits are needed to prevent carry passing through the
other SFR bits in the register when using INC DPS to toggle the pointer selection.
Data pointer select 1, data pointer select. These bits select the active data pointer.
SEL1, SEL = 00: Use DPX, DPH and DPL as DPTR
SEL1, SEL = 01: Use DPX1, DPH1 and DPL1 as DPTR
SEL1, SEL = 10: Use DPX2, DPH2 and DPL2 as DPTR
SEL1, SEL = 11: Use DPX3, DPH3 and DPL3 as DPTR
7 6 5 4 3 2 1 0
SFR 86h ID1 ID0 TSL AID SEL1 — — SEL
RW-0 RW-0 RW-0 R-0 R-0 R-1 RW-0 RW-0
R = Unrestricted read, W = Unrestricted write, -n = Value after reset
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