IFF.md

Conditional If

Uses: IF{[AL],NV,EQ,NE,LT,LE,GE,GT,CC,CS,VC,VS,PL,MI}

Mnemonics:

• ALways
• NeVer
• EQual
• Not Equal
• Less Than
• Less than or Equal
• Greater than or Equal
• Greater Than
• Carry Clear
• Carry Set
• oVerflow Clear
• oVerflow Set
• PLus (positive)
• MInus (negative)

Description:

Perform the next instruction conditionally. Functionally equivalent to incrementing the PC if the condition is false.

Condition Codes:

Flag	Modified
Carry	✗
Negative	✗
Overflow	✗
Zero	✗

Examples:

IFEQ        ; perform next instruction if zero
IFGT        ;    "     "        "      if greater than
IFCC        ;    "     "        "      if carry clear

Format:

│15     10│9     4│3    0│
┌─────────┬───────┬──────┐
│ 0000111 │ ----- │ CCCC │
└─────────┴───────┴──────┘

Legend:

Format	Use
0, 1	Literal bit
C	Condition code
-	Unused

Condition Code (C):

Flag	Meaning
0000	AL
0001	NV
0010	EQ
0011	NE
0100	LT
0101	LE
0110	GE
0111	GT
1000	CC
1001	CS
1010	VC
1011	VS
1100	PL
1101	MI
1110	—
1111	—