Btjrf Bit Test, Jump Relative On False - Samsung S3C84I8 User Manual

S3C84I8/F84I8/C84I9/F84I9
BTJRF
— Bit Test, Jump Relative on False
dst,src.b
BTJRF
If src(b) is a "0", then PC ← PC + dst
Operation:
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 currently in the
program counter. Otherwise, the instruction following the BTJRF instruction is executed.
No flags are affected.
Flags:
Format:
opc
NOTE: In the second byte of the instruction format, the source address is four bits, the bit address "b"
Given: R1 = 07H:
Example:
BTJRF
If the 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).
(note)
dst
src | b | 0
is three bits, and the LSB address value is one bit in length.
→
SKIP,R1.3
Bytes Cycles
3
PC jumps to SKIP location
INSTRUCTION SET
Opcode
(Hex)
10 37
Addr Mode
dst src
RA rb
6-23