I have finished the initialization portion of an SD Card interface (SPI Mode) to AVR. When reading the OCR, bit 15 is set indicating a 2.7-2.8 VDD voltage range.
What the heck does that mean ?
All of the information that I've found specifies the operational VDD range from 2.7 - 3.6V. This is considered a "high voltage" range, but seems to be standard at the moment. A "low voltage" range is from 1.6V - 3.6V for SDLV cards.
1. Does the OCR really have any useful meaning ?
2. Should I use CMD8 to query the card for voltage range ?