Jr Jump Relative - Samsung S3C80A5B User Manual

INSTRUCTION SET
JR
— Jump Relative
JR cc,dst
If cc is true, PC ← PC + dst
Operation:
If the condition specified by the condition code (cc) is true, the relative address is added to the
program counter and control passes to the statement whose address is now in the program
counter; otherwise, the instruction following the JR instruction is executed. (See list of condition
codes).
The range of the relative address is +127, –128, and the original value of the program counter is
taken to be the address of the first instruction byte following the JR statement.
Flags: No flags are affected.
Format:
cc | opc
NOTE:
Example: Given: The carry flag = "1" and LABEL_X = 1FF7H:
JR
If the carry flag is set (that is, if the condition code is true), the statement "JR C,LABEL_X" will
pass control to the statement whose address is now in the PC. Otherwise, the program instruction
following the JR would be executed.
6-48
(1)
dst
In the first byte of the two-byte instruction format, the condition code and the opcode are each
four bits.
→
C,LABEL_X
Bytes
2
PC = 1FF7H
Cycles Opcode
(Hex)
6 ccB
cc = 0 to F
S3C80A5B
Addr Mode
dst
RA