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

BRTC - Branch if the T Flag is Cleared
Instruction Set
Description:
Conditional relative branch. Tests the T flag and branches relatively to PC if T is cleared. 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 6,k).
Operation:
(i) If T = 0 then PC ← PC + k + 1, else PC ← PC + 1
Syntax: Operands: Program Counter:
(i) BRTC 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 01kk kkkk k110
I T H S V N Z C
- - - - - - - -
bst r3,5 ; Store bit 5 of r3 in T flag
brtc
...
tclear ; Branch if this bit was cleared
tclear: nop ; Branch destination (do nothing)
Words: 1 (2 bytes)
Cycles: 1 if condition is false
2 if condition is true
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