SAB80515 Datasheet, PDF (163/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

Instruction Set
JB
bit,rel
Function:
Jump if bit is set
Description:
If the indicated bit is a one, jump to the address indicated; 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 56
(01010110B). The instruction sequence
JB
P1.2,LABEL1
JB
ACC.2,LABEL2
will cause program execution to branch to the instruction at label LABEL2.
Operation:
JB
(PC) ← (PC) + 3
if (bit) = 1
then (PC) ← (PC) + rel
Encoding:
Bytes:
Cycles:
0010 0000
3
2
bit address
rel. address
Semiconductor Group
163