SN8P2318 Series
C-type LCD, RFC 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 26
Version 1.5
2.2.3 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. LVD24, LVD36 bits indicate LVD detecting
power voltage status.
086H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PFLAG
NT0
NPD
LVD36
LVD24
-
C
DC
Z
Read/Write
R/W
R/W
R
R
-
R/W
R/W
R/W
After reset
-
-
0
0
-
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 5
LVD36:
LVD 3.6V operating flag and only support LVD code option is LVD_H.
0 = Inactive (VDD > 3.6V).
1 = Active (VDD
≦
3.6V).
Bit 4
LVD24:
LVD 2.4V operating flag and only support LVD code option is LVD_M.
0 = Inactive (VDD > 2.4V).
1 = Active (VDD
≦
2.4V).
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.
