AT32UC3A3256S_2 Datasheet, PDF (824/1014 Pages) ATMEL Corporation – 32-bit AVR®Microcontroller

AT32UC3A3/A4
30. MultiMedia Card Interface (MCI)
Rev. 4.1.0.0
30.1 Features
• Compatible with Multimedia Card specification version 4.3
• Compatible with SD Memory Card specification version 2.0
• Compatible with SDIO specification version 1.1
• Compatible with CE-ATA specification 1.1
• Cards clock rate up to master clock divided by two
• Boot Operation Mode support
• High Speed mode support
• Embedded power management to slow down clock rate when not used
• Supports 2 Slots
– Each slot for either a MultiMediaCard bus (up to 30 cards) or an SD Memory Card
• Support for stream, block and multi-block data read and write
• Supports connection to DMA Controller
– Minimizes processor intervention for large buffer transfers
• Built in FIFO (from 16 to 256 bytes) with large memory aperture supporting incremental access
• Support for CE-ATA completion cignal disable command
• Protection against unexpected modification on-the-Fly of the configuration registers
30.2 Overview
The Multimedia Card Interface (MCI) supports the MultiMedia Card (MMC) specification V4.3,
the SD Memory Card specification V2.0, the SDIO V1.1 specificationand CE-ATA specification
V1.1.
The MCI includes a Command Register (CMDR), Response Registers (RSPRn), data registers,
time-out counters and error detection logic that automatically handle the transmission of com-
mands and, when required, the reception of the associated responses and data with a limited
processor overhead.
The MCI supports stream, block and multi block data read and write, and is compatible with the
DMA Controller, minimizing processor intervention for large buffers transfers.
The MCI operates at a rate of up to CLK_MCI divided by 2 and supports the interfacing of 2
Slots. Each slot may be used to interface with a MultiMediaCard bus (up to 30 Cards) or with a
SD Memory Card. Only one slot can be selected at a time (slots are multiplexed). The
SDCard/SDIO Slot Selection field in the SDCard/SDIO Register (SDCR.SDCSEL) performs this
selection.
The SD Memory Card communication is based on a nine-pin interface (clock, command, four
data and three power lines) and the MultiMedia Card on a seven-pin interface (clock, command,
one data, three power lines and one reserved for future use).
The SD Memory Card interface also supports MultiMedia Card operations. The main differences
between SD and MultiMedia Cards are the initialization process and the bus topology.
MCI fully supports CE-ATA Revision 1.1, built on the MMC System specification V4.0. The mod-
ule includes dedicated hardware to issue the command completion signal and capture the host
command completion signal disable.
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