STC micro STC8A8K64D4 Series - Enhanced Dual Data Pointer; Related Special Function Registers; 1 St 16-Bit Data Pointer Registers (DPTR0); 2 Nd 16-Bit Data Pointer Registers (DPTR1)

STC8A8K64D4 Series Manual
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24 Enhanced Dual Data Pointer
Two 16-bit data pointers are integrated in STC8A8K64D4 series of microcontrollers. The data pointers can be increased
or decreased automatically by the program control, and they can be switched automatically.
24.1 Related special function registers
Symbol
Description
Address
Bit Address and Symbol
Reset
Value
B7
B6
B5
B4
B3
B2
B1
B0
DPL
Data pointer low byte register
82H
0000,0000
DPH
Data pointer high byte register
83H
0000,0000
DPL1
2nd Data pointer low byte
E4H
0000,0000
DPH1
2nd Data pointer high byte
E5H
0000,0000
DPS
DPTR Selection Register
E3H
ID1
ID0
TSL
AU1
AU0
-
-
SEL
0000,0xx0
TA
DPTR Timing control register
AEH
0000,0000
24.1.1 1st 16-bit Data Pointer Registers (DPTR0)
Symbol
Address
B7
B6
B5
B4
B3
B2
B1
B0
DPL
82H
DPH
83H
DPL is Data pointer 0 low byte.
DPH is Data pointer 0 high byte.
The combination of DPL and DPH is the first 16-bit data pointer register DPTR0.
24.1.2 2nd 16-bit Data Pointer Registers (DPTR1)
Symbol
Address
B7
B6
B5
B4
B3
B2
B1
B0
DPL1
E4H
DPH1
E5H
DPL1 is Data pointer 1 low byte.
DPH1 is Data pointer 1 low byte.
The combination of DPL1 and DPH1 is the second 16-bit data pointer register DPTR1.
24.1.3 DPTR control register
Symbol
Address
B7
B6
B5
B4
B3
B2
B1
B0
DPS
E3H
ID1
ID0
TSL
AU1
AU0
-
-
SEL
ID1: DPTR1 auto-increment or auto-decrement mode control bit
0: DPTR1 auto-increment mode
1: DPTR1 auto-decrement mode
ID0: DPTR0 auto-increment or auto-decrement mode control bit
0: DPTR0 auto-increment mode
1: DPTR0 auto-decrement mode
TSL: DPTR0/DPTR1 auto-switch control bit (invert SEL automatically)
0: DPTR0/DPTR1 auto switch is disabled.
1: DPTR0/DPTR1 auto switch is enabled.
If the TSL bit is set, the SEL bit will be inverted automatically after the relevant instruction is executed.