AVR Instruction Set Nomenclature: Status Register (SREG ...

BRLO - Branch if Lower (Unsigned)
Instruction Set
Description:
Conditional relative branch. Tests the Carry flag (C) and branches relatively to PC if C 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 binary
number represented in Rd was smaller than 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 BRBS 0,k).
Operation:
(i) If Rd < Rr (C = 1) then PC ← PC + k + 1, else PC ← PC + 1
Syntax: Operands: Program Counter:
(i) BRLO k -64 ≤ k ≤ +63 PC ← PC + k + 1
PC ← PC + 1, if condition is false
16-bit Opcode:
Status Register (SREG) and Boolean Formulae:
Example:
1111 00kk kkkk k000
I T H S V N Z C
- - - - - - - -
eor r19,r19 ; Clear r19
loop: inc
...
r19 ; Increase r19
cpi r19,$10 ; Compare r19 with $10
brlo loop ; Branch if r19 < $10 (unsigned)
nop ; Exit from loop (do nothing)
Words: 1 (2 bytes)
Cycles: 1 if condition is false
2 if condition is true
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