SH7721 datasheet(1121/1524 Pages) RENESAS

1121 / 1524 page

Section 31

MultiMediaCard Interface (MMCIF)

Rev. 3.00 Jan. 18, 2008 Page 1059 of 1458

REJ09B0033-0300

(1)

Operation of Broadcast Commands

The CMD0, CMD1, CMD2, and CMD4 are broadcast commands. The sequence assigning relative

addresses to individual MMCs consists of these commands and the CMD3 command. In this

sequence, the CMD output format is open drain, and the command response is wired-OR. In this

case, the transfer clock frequency should be set sufficiently slow.

• All MMCs are initialized to the idle state by the CMD0.

• The operation condition register (OCR) of all MMCs is read via wired-OR, and MMCs that

cannot operate are deactivated by the CMD1.

The deactivated MMCs enter the ready state.

• The card identification (CID) of all MMCs in the ready state is read via wired-OR by the

CMD2.

The individual MMC compares its CID and data on the MMC_CMD, and if different, aborts

CID output. A single MMC in which the CID can be entirely output enters the acknowledge

state.

• A relative address (RCA) is given to the MMC in the acknowledge state by the CMD3.

The MMC to which the RCA is given enters the standby state.

• CMD2 and CMD3 are repeated, assigning RCAs to all MMCs in the ready state, entering each

into the standby state.

Note:

When the R2 response (17-byte command response) is required, the CTSEL0 bit should be

set to 1 since a timeout is generated during response reception if the CTSEL0 bit is set to

(2)

Operation of Relative Address Commands

The CMD7, CMD9, CMD10, CMD13, CMD15, CMD39, and CMD55 are relative address

commands that address the MMC by RCA. The relative address commands are used to read MMC

administration information and original information, and to change the specific card status.

The CMD7 sets one addressed MMC to the transfer state, and other MMCs to the standby state.

Only the MMC in the transfer state can execute a flash-memory operation command other than the

broadcast and relative address commands.

SH7721 Datasheet(PDF) 1121 Page - Renesas Technology Corp