rev_bits.asm

来自「PS2 Game Products Test-Jig source code,」· 汇编 代码 · 共 47 行

;=====================================================
; Files name : rev_bits.asm
; PSX Protocol Analyzer
; Rev: 1.0	Date: xx-02-2000	CC Li
;
; This sub-routine is to swap bits
; Swap bit 0 & 7; bit 1 & 6; bit 2 & 5 and bit 3 & 4
; The byte before swap bits should be put into register
; "pre_reverse"
; the byte after swap bits will be put into register
; pointed by FSR
; 
;=====================================================

	; Rotate through Carry bit to perform the 
	; swap function
CONVERT:
		MOVWF	CONVERT_BUFFER	
		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		rlf	CONVERT_BUFFER,F
		rrf	TEMP_BUFFER1,F

		MOVF	TEMP_BUFFER1,W
		return