Dear all,
i try to init my SD card with ATMEGA8 and i don't reach the goal becouse
the CMD1 don't return 0x00.
I attach my ASM code and i ask someone if can explain me if there is a mistake
in code.
Thank You.
Luigi.
[CODE];********************************************************
;* LIBRERIA DI FUNZIONI PER UTILIZZO DI SD CARD *
;* *
;* Nome: SD.inc *
;* Versione: 1.0 *
;* Data: 14/01/2012 *
;* Autore: Luigi Erroi *
;* *
;* Registri utilizzati: Work *
;* *
;* Variabili Utilizzate: NESSUNA *
;* *
;********************************************************
.EQU PortaSD = PORTB ; definisce porta della scheda SD
.EQU CS = 0 ; Pin CS della scheda SD
CMD0DATA: .db 0x40,0x00,0x00,0x00,0x00,0x95 ; SD card cmd 0
CMD1DATA: .db 0x41,0x00,0x00,0x00,0x00,0xFF ; SD card cmd 1
CMD9DATA: .db 0x49,0x00,0x00,0x00,0x00,0xFF ; SD card cmd 9
CMD8DATA: .db 0x48,0x00,0x00,0x01,0xAA,0x87 ; SD card cmd 8
CMD41DATA: .db 0x69,0x00,0x00,0x00,0x00,0xE5 ; SD card cmd 41
CMD55DATA: .db 0x77,0x00,0x00,0x00,0x00,0x65 ; SD card cmd 55
CMD58DATA: .db 0x7A,0x00,0x00,0x00,0x00,0xFD ; SD card cmd 55
;*******************************************
; Inizializzazione della scheda SD
;*******************************************
SD_Init:
sbi PortaSD,CS
push R23
ldi R23,10
ldi Work,0xFF
SD_Init_Seq:
dec R23
breq SD_Init_Seq2
rcall SPI_TX
rjmp SD_Init_Seq
SD_Init_Seq2:
rcall CMD0_Send
ldi R23,8
SD_CMD0_Loop:
dec R23
breq SD_Init_Exit
rcall SPI_RX
cpi Work,0x01
brne SD_CMD0_Loop
ldi Work,0x10
rcall Lcdlocate
ldi Work,'O'
rcall LcdSendData
ldi Work,'K'
rcall LcdSendData
rcall CMD8_Send
ldi R23,8
SD_CMD8_Loop:
dec R23
breq SD_Init_Exit2
rcall SPI_RX
cpi Work,0x05
brne SD_CMD8_Loop
ldi Work,0x12
rcall Lcdlocate
ldi Work,'O'
rcall LcdSendData
ldi Work,'K'
rcall LcdSendData
ldi R23,8
rcall CMD58_Send
SD_CMD58_Loop:
dec R23
breq SD_Init_Exit3
rcall SPI_RX
cpi Work,0x01
brne SD_CMD58_Loop
ldi Work,0x14
rcall Lcdlocate
ldi Work,'O'
rcall LcdSendData
ldi Work,'K'
rcall LcdSendData
SD_CMD1_:
ldi R23,255
rcall CMD1_Send
SD_CMD1_Loop:
dec R23
breq SD_Init_Exit4
rcall SPI_RX
cpi Work,0x00
brne SD_CMD1_Loop
ldi Work,0x16
rcall Lcdlocate
ldi Work,'O'
rcall LcdSendData
ldi Work,'K'
rcall LcdSendData
pop R23
sbi PortaSD,CS
ret
SD_Init_Exit:
pop R23
ldi Work,0x10
rcall Lcdlocate
ldi Work,'E'
rcall LcdSendData
ldi Work,'R'
rcall LcdSendData
ret
SD_Init_Exit2:
pop R23
ldi Work,0x12
rcall Lcdlocate
ldi Work,'E'
rcall LcdSendData
ldi Work,'R'
rcall LcdSendData
ret
SD_Init_Exit3:
pop R23
ldi Work,0x14
rcall Lcdlocate
ldi Work,'E'
rcall LcdSendData
ldi Work,'R'
rcall LcdSendData
ret
SD_Init_Exit4:
pop R23
ldi Work,0x16
rcall Lcdlocate
ldi Work,'E'
rcall LcdSendData
ldi Work,'R'
rcall LcdSendData
ret
;*******************************************
; Invio del CMD0 **** SD
;*******************************************
CMD0_Send:
cbi PortaSD,CS ; Seleziona CS (Attivo Basso)
ldi zh,high(CMD0DATA<<1) ; send cmd9
ldi zl,low(CMD0DATA<<1)
rcall Send_SD_Cmd
ret
;*******************************************
; Invio del CMD0 **** SD
;*******************************************
CMD1_Send:
cbi PortaSD,CS ; Seleziona CS (Attivo Basso)
ldi zh,high(CMD1DATA<<1) ; send cmd9
ldi zl,low(CMD1DATA<<1)
rcall Send_SD_Cmd
ret
;*******************************************
; Invio del CMD8 **** SD
;*******************************************
CMD8_Send:
cbi PortaSD,CS ; Seleziona CS (Attivo Basso)
ldi zh,high(CMD8DATA<<1) ; send cmd9
ldi zl,low(CMD8DATA<<1)
rcall Send_SD_Cmd
ret
;*******************************************
; Invio del CMD58 **** SD
;*******************************************
CMD58_Send:
cbi PortaSD,CS ; Seleziona CS (Attivo Basso)
ldi zh,high(CMD58DATA<<1) ; send cmd9
ldi zl,low(CMD58DATA<<1)
rcall Send_SD_Cmd
ret
;*******************************************
; Invio del ACMD41 **** SD
;*******************************************
ACMD41_Send:
cbi PortaSD,CS ; Seleziona CS (Attivo Basso)
ldi zh,high(CMD55DATA<<1) ; send cmd9
ldi zl,low(CMD55DATA<<1)
rcall Send_SD_Cmd
ldi zh,high(CMD41DATA<<1) ; send cmd9
ldi zl,low(CMD41DATA<<1)
rcall Send_SD_Cmd
ret
;*******************************************
; Invio del Comando **** scheda SD su SPI
;
; Z - punta ai 6 byte del comando
;*******************************************
Send_SD_Cmd:
push Work
push r18
ldi r18,6 ; command frames are 6 bytes
SSC_Loop:
lpm Work,z+ ; send them out
rcall SPI_TX
dec r18 ; repeat until done
brne SSC_Loop
pop r18
pop Work
ret[/CODE]
