GMS81004 Datasheet, PDF (28/101 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 2. Function Description
2.1.7.4 Half carry flag (H)
- After operation, set when there is a carry from bit3 of ALU or there is not a borrow
from bit4 of ALU.
- Can not be set by any instruction.
- Cleared by CLRV instruction like V flag.
2.1.7.5 Break flag (B)
- Set by BRK (S/W interrupt) instruction to distinguish BRK and TCALL instruction
having the same vector address.
2.1.7.6 G flag (G)
- Set and cleared by SETG, CLRG instruction.
- Assign direct page (0-page, 1-page).
- Addressable directly to RAM 1-page by SETG. and to RAM 0-page by CLRG.
2.1.7.7 Overflow flag (V)
- After operation, set when overflow or underflow occurs.
- In the case of BIT instruction, bit6 memory location is transferred to V-flag.
- Cleared by CLRV instruction, but not set by any instruction.
- Branch condition flag of BVS, BVC.
2.1.7.8 Negative flag (N)
- Set whenever the result of a data transfer or operation is negative (bit7 is set to
¡È1¡È).
- In the case of BIT instruction, bit7 of memory location is transferred to N-flag
- N-flag is not affected by CLR or SET instruction.
- Branch condition flag of BPL, BMI.
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