SN8P275X Series
8-bit micro-controller build-in 12-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 32
Version 0.7
2.1.4.5
PROGRAM FLAG
The PFLAG register contains the arithmetic status of ALU operation, system reset status and LVD detecting status.
NT0, NPD bits indicate system reset status including power on reset, LVD reset, reset by external pin active and
watchdog reset. 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
NT0 NPD -
-
-
C DC Z
Read/Write
R/W R/W -
-
- R/W R/W R/W
After
reset
- - - - - 0 0 0
Bit [7:6]
NT0, NPD:
Reset status flag.
NT0 NPD
Reset
Status
0
0
Watch-dog time out
0 1
Reserved
1
0
Reset by LVD
1
1
Reset by external Reset Pin
Bit 2
C:
Carry flag
1 = Addition with carry, subtraction without borrowing, rotation with shifting out logic “1”, comparison result
≥
0.
0 = Addition without 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.