f34x_msd_mmc_command.asm

C8051F340读写SD卡的程序

;//----------------------------------------------------------------------------
;// F34x_MSD_MMC_Command.asm
;//----------------------------------------------------------------------------
;// Copyright 2006 Silicon Laboratories, Inc.
;// http://www.silabs.com
;//
;// Program Description:
;//
;// This file contains commands for MMC card.
;//
;//
;//
;// How To Test:    See Readme.txt
;//
;//
;// FID:            34X000045
;// Target:         C8051F34x
;// Tool chain:     Keil
;// Command Line:   See Readme.txt
;// Project Name:   F34x_USB_MSD
;//
;// Release 1.1
;//    -All changes by PKC
;//    -09 JUN 2006
;//    -Removed individual SFR definitions and included c8051f340.inc
;//
;// Release 1.0
;//    -Initial Release
;//

$include (c8051f340.inc)               ; Include register definition file

MMC_COMMAND SEGMENT CODE
RSEG MMC_COMMAND

PUBLIC _READ_BYTES
PUBLIC _WRITE_BYTES

;///////////////////////////////
;/// function READ_BYTES
;///////////////////////////////

_READ_BYTES:
; r1,r2,r3 - pchar - pointer to data buffer
; r4,r5 - buffer length
		MOV		DPH,R2
		MOV   DPL,R1

		MOV		A,R5
		JNZ		BEGIN_READ
		MOV		A,R4
		JZ		FINISH_COPY
		DEC		R4

BEGIN_READ:		

		MOV		SPI0DAT,#0xFF		


COPY_LABEL:

READ_DATA:

		JNB   SPIF,$
		CLR		SPIF
		MOV		A,SPI0DAT				; read spi byte
		MOVX	@DPTR,A
		
		
		DJNZ	R5,NO_DEC_HI_COUNTER


DEC_HI_COUNTER:
		
		MOV		A,R4		
		JZ		FINISH_COPY 	
		DEC		R4

NO_DEC_HI_COUNTER:
			
		MOV		SPI0DAT,#0xFF	
		INC		DPL
		MOV		A,DPL
		JNZ		COPY_LABEL
		INC		DPH
		SJMP	COPY_LABEL

FINISH_COPY:

		RET

;///////////////////////////////
;/// END of function READ_BYTES
;///////////////////////////////

;///////////////////////////////
;/// function WRITE_BYTES
;///////////////////////////////


_WRITE_BYTES:

		MOV		DPH,R2
		MOV   DPL,R1
	
WRITE_COPY_LABEL:
		
		MOV		A,R5
		DEC		R5
		JNZ		WRITE_DATA	
		MOV		r5,#0xff
		MOV		A,R4			
		JZ		WRITE_FINISH_COPY 
		DEC		R4

WRITE_DATA:

		MOVX	A,@DPTR
		MOV		SPI0DAT,A		
		JNB   SPIF,$
		CLR		SPIF

		INC		DPL
		MOV		A,DPL
		JNZ		WRITE_DEC_HI_COUNTER
		INC		DPH

WRITE_DEC_HI_COUNTER:
	
		SJMP	WRITE_COPY_LABEL

WRITE_FINISH_COPY:

		RET

;////////////////////////////////
;/// END of function WRITE_BYTES
;////////////////////////////////




END