I’ve got a question about the connection of SD/MMC cards, based on the Olimex schematics.
According to the SD spec:
-DAT0-3/CMD/WP should have pullups,
-DAT0-3/CMD/CLK should have caps
However nowhere on their schematics do they have any caps, and they are inconsistent with their use of pullups. On some schematics they leave DAT1/DAT2 floating (which is a direct no-no AFAIK) and they don’t pull up CMD, and inconsistently pull up DAT0.
The spec says directly that not pulling up DAT1/DAT2 (even though they are unused) can cause high current consumption.
So did they goof in their design(s), or is there something that I don’t know here?
Thanks for any insight.