Holtek HT45F23A Manual page 31

HT45F23A/HT45F24A
TinyPower Flash MCU with OPA & Comparators
TM
STATUS Register
Bit
Name —
R/W —
POR —
Bit 7, 6 Unimplemented, read as "0"
Bit 5 TO: Watchdog Time-Out flag
0: After power up or executing the "CLR WDT" or "HALT" instruction
1: A watchdog time-out occurred.
Bit 4 PDF: Power down flag
0: After power up or executing the "CLR WDT" instruction
1: By executing the "HALT" instruction
Bit 3 OV: Overflow flag
0: no overflow
1: an operation results in a carry into the highest-order bit but not a carry out of the
Bit 2 Z: Zero flag
0: The result of an arithmetic or logical operation is not zero
1: The result of an arithmetic or logical operation is zero
Bit 1 AC: Auxiliary flag
0: no auxiliary carry
1: an operation results in a carry out of the low nibbles in addition, or no borrow
Bit 0 C: Carry flag
0: no carry-out
1: an operation results in a carry during an addition operation or if a borrow does not
C is also affected by a rotate through carry instruction.
Rev. 1.40
7 6 5
— TO
— R
— 0
highest-order bit or vice versa.
from the high nibble into the low nibble in subtraction
take place during a subtraction operation
31
4 3 2
PDF OV Z
R R/W R/W
0 x x
1 0
AC C
R/W R/W
x x
"x" unknown
March 29, 2019