SAB80515 Datasheet, PDF (166/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

Instruction Set
JMP
@A + DPTR
Function:
Jump indirect
Description:
Add the eight-bit unsigned contents of the accumulator with the sixteen-bit data
pointer, and load the resulting sum to the program counter. This will be the address
for subsequent instruction fetches. Sixteen-bit addition is performed (modulo 2¹⁶): a
carry-out from the low-order eight bits propagates through the higher-order bits.
Neither the accumulator nor the data pointer is altered. No flags are affected.
Example:
An even number from 0 to 6 is in the accumulator. The following sequence of
instructions will branch to one of four AJMP instructions in a jump table starting at
JMP_TBL:
JMP_TBL:
MOV
JMP
AJMP
AJMP
AJMP
AJMP
DPTR, #JMP_TBL
@A + DPTR
LABEL0
LABEL1
LABEL2
LABEL3
If the accumulator equals 04H when starting this sequence, execution will jump to
label LABEL2. Remember that AJMP is a two-byte instruction, so the jump
instructions start at every other address.
Operation:
JMP
(PC) ← (A) + (DPTR)
Encoding:
Bytes:
Cycles:
0111 0011
1
2
Semiconductor Group
166