SAB80515 Datasheet, PDF (167/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

Instruction Set
JNB
bit,rel
Function:
Jump if bit is not set
Description:
If the indicated bit is a zero, branch to the indicated address; otherwise proceed with
the next instruction. The branch destination is computed by adding the signed
relative-displacement in the third instruction byte to the PC, after incrementing the
PC to the first byte of the next instruction. The bit tested is not modified. No flags
are affected.
Example:
The data present at input port 1 is 11001010B. The accumulator holds 56H
(01010110B). The instruction sequence
JNB P1.3,LABEL1
JNB ACC.3,LABEL2
will cause program execution to continue at the instruction at label LABEL2.
Operation:
JNB
(PC) ← (PC) + 3
if (bit) = 0
then (PC) ← (PC) + rel.
Encoding:
Bytes:
Cycles:
0011 0000
3
2
bit address
rel. address
Semiconductor Group
167