gc80c520a CORERIVER Semiconductor, gc80c520a Datasheet - Page 121

• Manufacturer Part Number: gc80c520a
• Description: Midas1.0 Family Mask Rom/eprom/romless 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

JNB
Description:
Operation:
Encoding:
bit, rel
Function:
Example:
MiDAS1.0 Family
Cycles:
Bytes:
Jump if Bit Not set
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.
The data present at input port 1 is 11001010b. The Accumulator holds 56h
(01010110b). The instruction sequence,
JNB
JNB
will cause program execution to continue at the instruction at label LABEL2.
3
4
JNB
(PC)
IF (bit) = 0
0
THEN (PC)
←
0
(PC) + 3
P1.3, LABEL1
ACC.3, LABEL2
1
1
0 0 0 0
←
(PC) + rel
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bit address
relative