Flag Change Inhibit Prefix (Ncc); Table 2-11 Instructions Requiring Care When Using Flag Change Inhibit Prefix (Ncc) - Fujitsu MB90420/5 (A) Series Hardware Manual

2.9.3 Flag Change Inhibit Prefix (NCC)

When the flag change inhibit instruction is prefixed by the NCC, the flag change caused by execution of the
instruction can be inhibited.
n Flag change inhibit prefix
To inhibit unnecessary flag change, use the flag change inhibit prefix code (NCC). When the flag change
inhibit instruction is prefixed by the NCC, the flag change caused by execution of the instruction can be
inhibited. The inhibited flags are T, N, Z, V, and C. Table 2-11 shows the instructions requiring care when
using the flag change inhibit prefix.

Table 2-11 Instructions Requiring Care When Using Flag Change Inhibit Prefix (NCC)

Instruction Type
String instruction MOVS
SCEQ
FILS
Flag change
AND CCR, #imm8
instruction
OR CCR, #imm8
PS return POPW PS
instruction
ILM setting MOV ILM, #imm8
instruction
Interrupt INT
instruction
INT
Interrupt return
RETI
instruction
Context JCTX
Switch instruction
Instruction
MOVSW
SCWEQ
FILSW
#vct8 INT9
addr16 INTP addr24
@ A
CPU
Do not add the NCC prefix to the string
instructions.
The condition code register (CCR) changes
according to the instruction specification
irrespective of the prefix. The prefix affects up to
the next instruction.
The condition code register (CCR) changes
according to the instruction specification
irrespective of the prefix. The prefix affects up to
the next instruction.
The prefix affects up to the next instruction.
The condition code register (CCR) changes
according to the instruction specification
irrespective of the prefix.
The condition code register (CCR) changes
according to the instruction specification
irrespective of the prefix.
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