I'm going to use a PIC18f2520 to read/write files to a SD-card. I have a few questions/assumptions that I'm hoping someone can help with.
The SD-card requires a Vdd of 2.7-3.6V, so this must be a CMOS IC, yes?
I'll be using SPI for communications. Since the PIC uses TTL voltage levels, I'm assuming I need to convert a HIGH (5V) the PIC to 3.3V for the SD card for the SDO line (serial data out). I would also need to convert the serial CLK line down to 3.3V as well? Would a voltage divider be OK for this?
Reading a HIGH from the SD card should be fine -- I put 3.2V on a PIC input and it interpreted this as HIGH.
Thanks.
SD reference manual:
http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
The SD-card requires a Vdd of 2.7-3.6V, so this must be a CMOS IC, yes?
I'll be using SPI for communications. Since the PIC uses TTL voltage levels, I'm assuming I need to convert a HIGH (5V) the PIC to 3.3V for the SD card for the SDO line (serial data out). I would also need to convert the serial CLK line down to 3.3V as well? Would a voltage divider be OK for this?
Reading a HIGH from the SD card should be fine -- I put 3.2V on a PIC input and it interpreted this as HIGH.
Thanks.
SD reference manual:
http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf