Klikwae The Info

All instructions of the mcs-51 microcontroller are shown on 79 pages.

For example the instruction 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:
0 0 1 0 0 0 0 0 + bit address + rel. address
Bytes: 3
Cycles: 2

source : Batronix
download : Microcontroller Instruction Set
(79 pages, 308 kbytes)

Tags: download, electronic, microcontroller, programming, source

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