X-Git-Url: http://cloudbase.mooo.com/gitweb/avrcpm.git/blobdiff_plain/94175893adca548862102caa29fd8c998d7d0e67..8b13b36c6542ac4fac3a69ae45f7e296f7754bdb:/mmc.asm

diff --git a/mmc.asm b/mmc.asm
index 1a04542..49a1b9c 100644
--- a/mmc.asm
+++ b/mmc.asm
@@ -591,6 +591,81 @@ mmc_rdex:
 .endif
 	ret
 
+
+;--------------------------------------------------------------
+; Read word 
+; TODO: Read Word to ZL,ZH at given ZL/ZH Offset
+; Need for reading of single FAT16 Entrys without killing the
+; Entrys in hostbuffer...
+;
+; 	in	zh,zl:		Pointer to Word within the Sector to read	
+;   in	yh..xl:	Start sector number (LBA)
+;	out	xh,xl	: word thats been read
+
+mmcReadWord:
+.if MMC_DEBUG > 1
+	printnewline
+	printstring	"mmcRdWord "
+.endif
+	lds		_tmp0,mmcStat
+	ldi		temp,RES_NOTRDY
+	sbrc	_tmp0,MMCST_NOINIT
+	ret
+	
+	spi_clkfast
+	lds		temp,mmcCardType
+	sbrs	temp,log2(CT_BLOCK)
+ 	rcall	mul_yx_512		;Convert to byte address  (*512)
+
+	ldi		temp2,CMD17
+	rcall	mmcCmd
+	ldi		temp2,RES_ERROR
+	brne	mmc_rdexw
+	
+; Receive a data packet from MMC
+
+	ldiw	y,512			;Number of bytes to tranfer
+	ldi		temp,200		;Wait for data packet in timeout of 200ms.
+	sts		delay_timer1,temp
+mmc_rcvw_wl:
+	rcall	spi_rcvr
+	cp		temp,_255
+	brne	mmc_rcvw_start
+	lds		temp2,delay_timer1
+	cpi		temp2,0
+	brne	mmc_rcvw_wl
+mmc_rcvw_start:
+	cpi		temp,0xFE		;If not valid data token, 
+	ldi		temp2,RES_ERROR
+	brne	mmc_rdexw
+	
+	rcall	spi_rcvr		;Shift in first byte.
+	out		SPDR,_255		;Start shift in next byte.
+mmc_rcvw_rl:
+	sbiw	yl,1
+	breq	mmc_rcvw_rle
+	//st		z+,temp
+	spi_waitm
+	in		temp,SPDR
+	out		SPDR,_255
+	rjmp	mmc_rcvw_rl
+
+mmc_rcvw_rle:
+	//st		z+,temp			;Store last byte in buffer 
+	rcall	spi_wait		;      while SPI module shifts in crc part1.
+	rcall	spi_rcvr		;Read second crc.
+	
+	ldi		temp2,RES_OK		;Return success
+mmc_rdexw:
+	rcall	mmcDeselect
+	spi_disable
+	mov	temp,temp2
+.if MMC_DEBUG > 1
+	printstring	"RdWordRes: "
+	rcall	printhex
+	printstring	" "
+.endif
+	ret
 
 ;--------------------------------------------------------------
 ; Write sector