37
2.5.6
Branching Instructions
Table 2.9 describes the branching instructions. Figure 2.8 shows their object code formats.
Table 2.9
Branching Instructions
Instruction
Size
Function
Bcc
—
Branches to the designated address if the specified condition is true.
The branching conditions are given below.
Mnemonic
Description
Condition
BRA (BT)
Always (true)
Always
BRN (BF)
Never (false)
Never
BHI
High
C
∨
Z = 0
BLS
Low or same
C
∨
Z = 1
BCC (BHS)
Carry clear (high or same)
C = 0
BCS (BLO)
Carry set (low)
C = 1
BNE
Not equal
Z = 0
BEQ
Equal
Z = 1
BVC
Overflow clear
V = 0
BVS
Overflow set
V = 1
BPL
Plus
N = 0
BMI
Minus
N = 1
BGE
Greater or equal
N
⊕
V = 0
BLT
Less than
N
⊕
V = 1
BGT
Greater than
Z
∨
(N
⊕
V) = 0
BLE
Less or equal
Z
∨
(N
⊕
V) = 1
JMP
—
Branches unconditionally to a specified address
BSR
—
Branches to a subroutine at a specified address
JSR
—
Branches to a subroutine at a specified address
RTS
—
Returns from a subroutine