NEC 78K/0S Series User Manual page 110

DBNZ
[Instruction format]
[Operation]
[Operand]
Mnemonic
DBNZ B, $addr16
C, $addr16
saddr, $addr16
[Flag]
Z AC
[Description]
•
One is subtracted from the destination operand (dst) contents specified with the 1st operand and the
subtraction result is stored in the destination operand (dst).
•
If the subtraction result is not 0, program branches to the address indicated with the 2nd operand ($addr16).
When the subtraction result is 0, no processing is carried out and the subsequent instruction is executed.
•
The flag remains unchanged.
[Description example]
DBNZ B, $1215H; The B register contents are decremented. If the result is not 0, program branches to 1215H
(with the start of this instruction set in the range of addresses 1194H to 1293H).
110
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
DBNZ dst, $addr16
dst ← dst – 1,
then PC ← PC + b + jdisp16 if dst R1 ≠ 0
Operand (dst, $addr16)
CY
User's Manual U11047EJ3V0UM00
Decrement and Branch if Not Zero
b (Number of bytes)
2
2
3
Conditional Loop (R1 ≠ ≠ ≠ ≠ 0)