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8XC251SA, SB, SP, SQ USER'S MANUAL
Operation:
JLE
(PC) ← (PC) + 2
IF (Z) = 1 OR (CY) = 1
THEN (PC) ← (PC) + rel
JMP @A+DPTR
Function:
Jump indirect
Description:
Add the 8-bit unsigned contents of the accumulator with the 16-bit data pointer and load the
resulting sum into the lower 16 bits of the program counter. This is the address for
subsequent instruction fetches. The contents of the accumulator and the data pointer are
not affected.
Flags:
CY
—
Example:
The accumulator contains an even number from 0 to 6. The following sequence of instruc-
tions branch to one of four AJMP instructions in a jump table starting at JMP_TBL:
JMP_TBL:
If the accumulator contains 04H at the start this sequence, execution jumps to LABEL2.
Remember that AJMP is a two-byte instruction, so the jump instructions start at every other
address.
Binary Mode
Bytes:
States:
[Encoding]
0 1 1 1
Hex Code in:
Binary Mode = [Encoding]
Source Mode = [Encoding]
Operation:
JMP
(PC.15:0) ← (A) + (DPTR)
JNB bit51,rel
JNB bit,rel
Function:
Jump if bit not set
Description:
If the specified bit is clear, branch to the specified 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.
A-70
AC
—
MOV
DPTR,#JMP_TB
JMP
AJMP
@A+DPTR
AJMP
LABEL0
AJMP
LABEL1
AJMP
LABEL2
LABEL3
Source Mode
1
1
5
5
0 0 1 1
OV
N
—
—
L
Z
—
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