Sfr Definition 12.3. Sp: Stack Pointer; Sfr Definition 12.4. Acc: Accumulator; Sfr Definition 12.5. B: B Register - Silicon Laboratories C8051T620 Manual

C8051T620/1/6/7 & C8051T320/1/2/3

SFR Definition 12.3. SP: Stack Pointer

Bit 7
Name
Type
Reset 0
SFR Address = 0x81
Bit Name
7:0 SP[7:0] Stack Pointer.
The Stack Pointer holds the location of the top of the stack. The stack pointer is incre-
mented before every PUSH operation. The SP register defaults to 0x07 after reset.

SFR Definition 12.4. ACC: Accumulator

Bit 7
Name
Type
Reset 0
SFR Address = 0xE0; Bit-Addressable
Bit Name
7:0 ACC[7:0] Accumulator.
This register is the accumulator for arithmetic operations.

SFR Definition 12.5. B: B Register

Bit 7
Name
Type
Reset 0
SFR Address = 0xF0; Bit-Addressable
Bit Name
7:0 B[7:0] B Register.
This register serves as a second accumulator for certain arithmetic operations.
74
6 5 4
0 0 0
6 5 4
0 0 0
6 5 4
0 0 0
Rev. 1.2
3 2
SP[7:0]
R/W
0 1
Function
3 2
ACC[7:0]
R/W
0 0
Function
3 2
B[7:0]
R/W
0 0
Function
1 0
1 1
1 0
0 0
1 0
0 0