Samsung S3F80JB Btjrf Bit Test, Jump Relative on False, Example Given R1 = 07H, Btjrf SKIP,R1.3

S3F80JBINSTRUCTION SET

BTJRF — Bit Test, Jump Relative on False

BTJRF dst,src.b

Operation: If src(b) is a "0", then PC ← PC + dst

The specified bit within the source operand is tested. If it is a "0", the relative address is added to the program counter and control passes to the statement whose address is now in the PC; otherwise, the instruction following the BTJRF instruction is executed.

Flags: No flags are affected.

Format:

(Note 1)

opc src b 0 dst

Bytes	Cycles	Opcode	Addr Mode
		(Hex)	dst	src
3	10	37	RA	rb

NOTE: In the second byte of the 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:

BTJRF SKIP,R1.3 → PC jumps to SKIP location

If working register R1 contains the value 07H (00000111B), the statement "BTJRF SKIP,R1.3" tests bit 3. Because it is "0", the relative address is added to the PC and the PC jumps to the memory location pointed to by the SKIP. (Remember that the memory location must be within the allowed range of + 127 to – 128.)

6-23