Description:

Conditional relative branch. Tests the Carry flag (C) and branches relatively to PC if C is cleared. If the instruction is executed immediately after execution of any of the instructions CP, CPI, SUB or SUBI the branch will occur if and only if the unsigned binary number represented in Rd was greater than or equal to the unsigned 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 BRBC 0,k).

Operation:

If Rd ≥Rr (C = 0) then PC ← PC + k + 1, else PC ← PC + 1

Syntax: Operands: Program Counter:

BRSH k -64 ≤ k ≤ +63 PC ← PC + k + 1

PC ← PC + 1, if condition is false

16-bit Opcode:

1111

01kk

kkkk

k000

Status Register (SREG) and Boolean Formula:

I

T

H

S

V

N

Z

C

-

-

-

-

-

-

-

-

Example:

subi r19,4 ; Subtract 4 from r19
brsh highsm ; Branch if r19 >= 4 (unsigned)
...
highsm:nop ; Branch destination (do nothing)

Words: 1 (2 bytes)

Cycles: 1 if condition is false

2 if condition is true