Datasheet

FS98O22
Rev. 1.6 24/146
3.3.3. STATUS Register
The STATUS register contains the arithmetic status of ALU and the RESET status. The STATUS register is
similar to other registers, and can be the destination for any instruction. If the STATUS register is the
destination for an instruction that affects the Z, DC or C bit, then the writing to these three bits is disabled.
These bits are set or cleared according to the device logic. The TO and PD bits are not writable.
Register STATUS at address 04H
property R/W-0 R/W-0 U-X R-0 R-0 R/W-X R/W-X R/W-X
STATUS
IRP1 IRP0 PD TO DC C Z
Bit7 Bit0
Bit 7 IRP1: Indirect address 1 page select
1 = Indirect address 1 extend memory address is set (Memory 1XXH)
0 = Indirect address 1 extend memory address is Not set (Memory 0XXH)
Bit 6 IRP0: Indirect address 0 page select
1 = Indirect address 0 extend memory address is set (Memory 1XXH)
0 = Indirect address 0 extend memory address is Not set (Memory 0XXH)
Bit 4 PD: Power down Flag.
1 = By execution of SLEEP instruction
0 = After power-on reset
Bit 3 TO: Watch Dog Time Out Flag. Cleared by writing 0 and Set by Watch Dog Time Out
1 = A Watch Dog Timer time-out occurred
0 = After power-on reset
Bit 2 DC: Digit Carry Flag/borrow Flag, for ADDWFI and SUBWFI
(for borrow the polarity is reversed)
1 = If there is a carry out from the 4
th
bit of the result
0 = No carry out from the 4
th
bit of the result
Bit 1 C: Carry Flag/borrow Flag (~Borrow)
(for borrow the polarity is reversed)
1 = If there is a carry out from the Most Significant bit of the result
0 = No carry out from the most significant bit of the result
Bit 0 Z: Zero Flag
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is NOT zero
FORTUNE'
Properties
For Reference Only