SD-карты и контроллеры, реализации FAT

[shurik-ua]

я когдато писал на VHDL чтение карты в SPI режиме - вот фрагмент инициализации

--INITIALISATION start
			when SD_INIT =>
				sd_stage <= CS_HI_80_PULSES;
				counter <= 127;						--128 pulses while CS is high, CMD must be high too
			when CS_HI_80_PULSES =>
				counter <= counter - 1;							
				if counter = 0 then
					sd_stage <= SEND_CMD_00;						
					SD_CS_n <= '0';
				end if;
			when SEND_CMD_00 =>
				sd_stage <= SEND_CMD;						
				next_stage <= SEND_CMD_08;			
				command <= X"FF400000000095";									
				recv_bits <= 8;						-- responce 8 bits
			when SEND_CMD_08 =>
				next_stage <= SEND_CMD_55;
				sd_stage <= SEND_CMD;
				command <= X"FF48000001AA87";							
				recv_bits <= 40;					-- responce 40 bits
			when SEND_CMD_55 =>
				sd_ver_2 <= not responce(34);
				sd_stage <= SEND_CMD;						
				next_stage <= SEND_ACMD_41;				
				command <= X"FF7700000000FF";						
				recv_bits <= 8;
			when SEND_ACMD_41 =>
				sd_stage <= SEND_CMD;						
				next_stage <= PROCESSING_INIT_1;				
				command <= X"FF69" & '0' & sd_ver_2 & "000000" & X"000000FF";																	
				recv_bits <= 8;	
			when PROCESSING_INIT_1 =>						
				if responce(0) = '0' then
					if	sd_ver_2 = '0' then
						sd_stage <= READY;
						sdhc <= '0';
					else
						sd_stage <= SEND_CMD_59;
					end if;
				else
					sd_stage <= SEND_CMD_55;
				end if;
			when SEND_CMD_59 =>
				sd_stage <= SEND_CMD;						
				next_stage <= PROCESSING_INIT_2;				
				command <= X"FF7B00000000FF";						
				recv_bits <= 8;	
			when PROCESSING_INIT_2 =>
				if responce (6 downto 0) = "0000000" then
					sd_stage <= SEND_CMD_16;
				else
					sd_stage <= SEND_CMD_59;
				end if;
			when SEND_CMD_16 =>
				sd_stage <= SEND_CMD;						
				next_stage <= PROCESSING_INIT_3;
				command <= X"FF5000000200FF";						
				recv_bits <= 8;							
			when PROCESSING_INIT_3 =>
				if responce (6 downto 0) = "0000000" then
--					if	sd_ver_2 = '0' then
--						sd_stage <= READY;
--						sdhc <= '0';
--					else
						sd_stage <= SEND_CMD;
						next_stage <= PROCESSING_INIT_4;
						command <= X"FF7A00000000FF";						
						recv_bits <= 40;							
--					end if;
				else
					sd_stage <= SEND_CMD_16;
				end if;
			when PROCESSING_INIT_4 =>
				sdhc <= responce(30);
				sd_stage <= READY;				
--INITIALISATION end

вдруг пригодится ) - писал по даташиту на сд карты и даже работало )