SH7763 Datasheet, PDF (1392/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 31 Multimedia Card Interface (MMCIF)
31.4 Operation
The multimedia card is an external storage media that can be easily connected or disconnected.
The MMCIF controls data transfer with the multimedia card and operates in MMC mode.
Insert a card and supply power to it. Then operate the MMCIF by applying the transfer clock after
setting an appropriate transfer clock frequency. In this case, MMC_VDDON and MMC_ODMOD
are available for card power supply control and open-drain mode control, respectively.
A series of operations  starting with sending out commands, receiving a command response,
data transmit/receive, receiving data responses, etc. is called the command sequence. The
command response starts with sending out commands by setting the START bit in CMDSTRT
and ends with the completion of all data transmit/receive and responses. The multimedia card may
go into the data busy state in which the card receives only special commands caused by writing to
or erasing the flash memory in the card. The data busy state is indicated by a ‘0’ output from the
card through the DAT pin.
Notes: Do not connect or disconnect the card during command sequence execution or in the data
busy state.
31.4.1 Operations in MMC Mode
MMC mode is an operating mode in which the transfer clock is output from the MMC_CLK pin,
command transmission/response reception occurs via the MMC_CMD pin, and data is
transmitted/received via the MMC_DAT pin. In this pin configuration, the next command can be
issued while data is being transmitted or received.
This feature is utilized for multiblock or stream transfer. The CMD12 command is an example of
where the current command sequence is aborted.
In MMC mode, broadcast commands that simultaneously issue commands to multiple cards are
supported. After information from the inserted cards is recognized through a broadcast command,
a relative address is given to each card. One card is selected by the relative address with other
cards deselected, and then various commands are issued to the selected card.
Commands in MMC mode are basically classified into three types: broadcast, relative address, and
flash memory operation commands. The card can be operated by issuing these commands
appropriately according to the card state.
Rev. 1.00 Oct. 01, 2007 Page 1326 of 1956
REJ09B0256-0100