BTEST

Operation

Tests the indexed destination bit without writing it, sets Z when it is clear, and clears NCV.

Assembler Syntax

BTEST Rn(b), <ea>(e)

BTEST imm6(i), <ea>(e)

BTEST Rn(b), Rn(e)

BTEST imm6(i), Rn(e)

Privilege

Unprivileged

Repeat eligibility

REP eligible; REPcc observes computed

Tests the destination bit selected by the low six bits of the bit index and writes FLAGS.Z from whether that bit was clear while clearing FLAGS.N, FLAGS.C, and FLAGS.V, without changing the destination. The B-sized 0 or 1 value of the old tested bit supplies the REPcc observed value.

2.75in