DESCRIPTION OF INSTRUCTIONS
285
35. DJNZ Rr, code address (Decrement register, and jump if not zero)
11011r2 r1 r0
70
Instruction code
Relative offset
Operations
Number of bytes
Number of cycles
Flags
(PSW)
Description
: Byte 1
R7 R6 R5 R4 R3 R2 R1 R0
70
Byte 2
(PC)←(PC)+2
(Rr)←(Rr)–1 r=0 thru 7
IF (Rr)≠0
THEN
(PC)←(PC)+relative offset
:
C AC F0 RS1 RS0 OV F1 P
:
:
:
The register r contents are decremented by 1. Control is shifted
to a relative jump address if the register r contents are not 0 as
a result of the decrement. Control is shifted to the next address
following this instruction if the result is 0.
:
2
2
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