Assembly之instruction之JC

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JC　　　　Jump if carry set
JHS　　　 Jump if higher or same

Syntax 　　JC　　label

　　　　　　JHS 　label

Operation

　　　　If C = 1: PC + 2 × offset −> PC
　　　　If C = 0: execute following instruction

Description

　　 The status register carry bit (C) is tested. If it is set, the 10-bit signed offset contained in the instruction LSBs is added to the program counter. If C is reset, the next instruction following the jump is executed. JC (jump if carry/higher or same) is used for the comparison of unsigned numbers (0 to 65536).

Status Bits

　　Status bits are not affected.

Example

　　The P1IN.1 signal is used to define or control the program flow.

1 BIT #01h,&P1IN 　　; State of signal −> Carry
2 JC PROGA 　　　　　 ; If carry=1 then execute program routine A
3   ...... 　　　　　 ; Carry=0, execute program here

Example

　　 R5 is compared to 15. If the content is higher or the same, branch to LABEL.

1 CMP #15,R5
2 JHS LABEL 　  　; Jump is taken if R5 ≥ 15
3   ...... 　　　　　 ; Continue here if R5 < 15

Assembly之instruction之JC

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原文地址：http://www.cnblogs.com/mengdie/p/4681102.html