Reset - SanDisk SDSDB-32-201-80 - Industrial Grade Flash Memory Card Product Manual

Secure Digital (SD) Card Protocol Description
SPI Operation CMD0
Mode CS Asserted ("0")
Card is Busy
or Host ommitted
voltage range
No response
(non-valid command)
Must be an MMC
Start MMC
initialization process
starting at CMD1
Card Identification Mode
Data Transfer Mode
Figure 4-7. SD Card State Diagram (Card Identification Mode)

4.3.1. Reset

GO_IDLE_STATE (CMD0) is the software reset command and sets each SD Card to Idle State regardless of the
current card state. SD Cards in Inactive State are not affected by this command.
After power-on by the host, all SD Cards are in Idle State, including the cards that were in Inactive State. Note that
at least 74 clock cycles are required prior to starting bus communication.
After power-on or CMD0, all SD Cards' CMD lines are in input mode, waiting for the start bit of the next
command. The cards are initialized with a default relative card address (RCA=0x0000) and with a default driver
stage register setting (lowest speed, highest driving current capability).
4-6
Power On
Idle State
(idle)
ACMD41
Ready State
(ready)
CMD2
Identification
State (ident)
CMD3
Stand-by
State (stby)
SanDisk Secure Digital (SD) Card Product Manual, Rev. 1.9 © 2003 SANDISK CORPORATION
CMD0
Inactive State
(ina)
Cards with non-compatible
voltage range
Card responds
with new RCA
CMD3
Card responds
with new RCA
From all states except (ina)
CMD15
From all States in Data
Transfer Mode