S3F84B8_UM_REV 1.00 6 INSTRUCTION SET
6-23
6.3.11 BTJRT — BIT TEST, JUMP RELATIVE ON TRUE
BTJRT dst,src.b
Operation: If src(b) is a “1”, then PC PC + dst.
The specified bit within the source operand is tested. If the bit is “1”, the relative address is added
to the program counter and control passes to the statement whose address is in the PC;
otherwise, the instruction following the BTJRT instruction is executed.
Flags: No flags are affected.
Format:
(NOTE)
Bytes Cycles Opcode
(Hex)
Addr Mode
dst src
opc src | b | 1 dst 3 10 37 RA rb
NOTE: In the second byte of instruction format, the source address is four bits, the bit address ‘b’ is three bits, and
the LSB address value is one bit in length.
Example: Given R1 = 07H:
BTJRT SKIP,R1.1
If the value of working register R1 is 07H (00000111B), the statement “BTJRT SKIP,R1.1” tests
bit one in the source register (R1). Since the bit is “1”, the relative address is added to the PC,
which then jumps to the memory location pointed to by SKIP. (Note that the memory location
must be within the allowed range of + 127 to – 128.)
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