Instruction Set
3-50 RISC 16Bit CPU
JNC Jump if carry not set
JLO Jump if lower
Syntax JNC label
JLO label
Operation if C = 0: PC + 2 × offset > PC
if C = 1: execute following instruction
Description The status register carry bit (C) is tested. If it is reset, the 10-bit signed offset
contained in the instruction LSBs is added to the program counter. If C is set,
the next instruction following the jump is executed. JNC (jump if no carry/lower)
is used for the comparison of unsigned numbers (0 to 65536).
Status Bits Status bits are not affected.
Example The result in R6 is added in BUFFER. If an overflow occurs, an error handling
routine at address ERROR is used.
ADD R6,BUFFER ; BUFFER + R6 > BUFFER
JNC CONT ; No carry, jump to CONT
ERROR ...... ; Error handler start
......
......
......
CONT ...... ; Continue with normal program flow
......
......
Example Branch to STL2 if byte STATUS contains 1 or 0.
CMP.B #2,STATUS
JLO STL2 ; STATUS < 2
...... ; STATUS 2, continue here