K60P100M100SF2RM Datasheet, PDF (1646/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Initialization/application of SDHC
return; //
} // end of if (no error ...
else if (errors other than time-out occur) { // command/response pair is corrupted
deal with it by program specific manner;
} // of else if (response time-out
else { // CMD55 is refuse, it must be MMC card or CE-ATA card
if (card is already labelled as SDCombo) { // change label
re-label the card as SDIO;
ignore the error or report it;
return; // card is identified as SDIO card
} // of if (card is ...
send_command(SEND_OP_COND, <voltage range>, <...>);
if (RESP_TIMEOUT == wait_for_response(SEND_OP_COND)) { // CMD1 is not accepted, either
label the card as UNKNOWN;
return;
} // of if (RESP_TIMEOUT ...
if (check for CE-ATA signature succeeded) { // the card is CE-ATA
store CE-ATA specific info from the signature;
label the card as CE-ATA;
} // of if (check for CE-ATA ...
else label the card as MMC;
} // of else
}
52.6.2.4 Card registry
Card registry for the MMC and SD/SDIO/SD combo cards are different. For CE-ATA, it
enters the tran state after reset is completed.
For the SD card, the identification process starts at a clock rate lower than 400 kHz and
the power voltage higher than 2.7 V (as defined by the card specification). At this time,
the CMD line output drives are push-pull drivers instead of open-drain. After the bus is
activated, the host will request the card to send their valid operation conditions. The
response to ACMD41 is the operation condition register of the card. The same command
shall be send to all of the new cards in the system. Incompatible cards are put into the
inactive state. The host then issues the command, All_Send_CID (CMD2), to each card
to get its unique card identification (CID) number. Cards that are currently unidentified
(in the ready state), send their CID number as the response. After the CID is sent by the
card, the card goes into the identification state.
The host then issues Send_Relative_Addr (CMD3), requesting the card to publish a new
relative card address (RCA) that is shorter than the CID. This RCA will be used to
address the card for future data transfer operations. Once the RCA is received, the card
changes its state to the standby state. At this point, if the host wants the card to have an
alternative RCA number, it may ask the card to publish a new number by sending another
Send_Relative_Addr command to the card. The last published RCA is the actual RCA of
the card.
The host repeats the identification process with CMD2 and CMD3 for each card in the
system until the last CMD2 gets no response from any of the cards in system.
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K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.