Description:

Conditional relative branch. Tests the Zero flag (Z) and branches relatively to PC if Z is set. If the instruction is executed immediately after any of the instructions CP, CPI, SUB or SUBI, the branch will occur if and only if the unsigned or signed binary number represented in Rd was equal to the unsigned or signed binary number represented in Rr. This instruction branches relatively to PC in either direction (PC - 63 ≤ destination ≤ PC + 64). The parameter k is the offset from PC and is represented in two's complement form. (Equivalent to instruction BRBS 1,k).

Operation:

If Rd = Rr (Z = 1) then PC <- PC + k + 1, else PC <- PC + 1

Syntax: Operands: Program Counter:

BREQ k -64 ≤ k ≤ +63 PC <- PC + k + 1

PC <- PC + 1, if condition is false

16-bit Opcode:

1111

00kk

kkkk

k001

Status Register (SREG) and Boolean Formulae:

I

T

H

S

V

N

Z

C

-

-

-

-

-

-

-

-

Example:

cp r1, r0 ; Compare registers r1 and r0
breq equal ; Branch if registers equal
...
equal: nop ; Branch destination (do nothing)

Words: 1 (2 bytes)

Cycles: 1 if condition is false

2 if condition is true