SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 32
V1.7
2.1.7
PROGRAM FLAG
The PFLAG register contains the arithmetic status of ALU operation, C, DC, Z bits indicate the result status of ALU
operation.
086H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PFLAG
-
-
-
-
-
C
DC
Z
Read/Write
-
-
-
-
-
R/W
R/W
R/W
After reset
-
-
-
-
-
0
0
0
Bit 2
C:
Carry flag
1 = Addition with carry, subtraction without borrowing, rotation with shifting out logic “1”, comparison result
≥ 0.
0 = Addition witho
ut carry, subtraction with borrowing signal, rotation with shifting out logic “0”, comparison
result < 0.
Bit 1
DC:
Decimal carry flag
1 = Addition with carry from low nibble, subtraction without borrow from high nibble.
0 = Addition without carry from low nibble, subtraction with borrow from high nibble.
Bit 0
Z:
Zero flag
1 = The result of an arithmetic/logic/branch operation is zero.
0 = The result of an arithmetic/logic/branch operation is not zero.
Note: Refer to instruction set table for detailed information of C, DC and Z flags.