Users Guide: DS80C390 Supplement Manual
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. 










