Specifications

Functional Description
30-Dec-2010 CM-X300 Reference Guide Rev 1.31 33
Table 26 USB3 CAMI Port Signals
CM-X300 Signal
Name
Type
Description
{USBD-P, USBD-N}
I/O
USB 2.0 Device Data
Differential pair that connects to the USB 2.0 device controller.
3.3.10 MMC/SD/SDIO Controller
The Multimedia Card (MMC) and Secure Digital (SD/SDIO) controller (MMC/SD/SDIO
controller) provides a software-accessible hardware link between the processor and the
MMC stack (a set of memory cards). The MMC/SD/SDIO controller supports Multimedia
Card, Secure Digital, and Secure Digital I/O communication protocols.
 The MMC module manages the MMC system, which is low-cost data storage and
communications system. The MMC module is based on the standards outlined in the
Multimedia Card System Specification Version 3.3.1. The SD module manages one
SD or SDIO card based on the standards outlined in the SD Memory Card
Specification Version 1.10 and SDIO Card Specification Version 1.0.
The MMC/SD/SDIO controller manages the translation protocol from a standard MMC bus
or from a serial peripheral interface (SPI) bus to the MMC stack. Software must select
either the MMC/SD/SDIO mode or SPI mode to establish the communication protocol for
the MMC/SD/SDIO controller.
3.3.10.1 MMC/SD/SDIO Controller Features
 A response FIFO (MMC_RES)
 Two transmit FIFOs (MMC_TXFIFO1 and MMC_TXFIFO2)
 Two receive FIFOs (MMC_RXFIFO1 and MMC_RXFIFO2)
 Two operating modes:
 MMC/SD/SDIO mode for MMC, SD, and SDIO communication protocols.
 SPI mode for the SPI communications protocol.
 One-bit and 4-bit data transfers for MMC, SD, and SDIO communication protocols
 Data transfer clock up to 26 MHz
 Based on FIFO status, turn clock on and off to prevent overflows and under-runs
 Support for all valid MMC and SD/SDIO protocol data-transfer modes
 Interrupt-based application interface to control software interaction
 Stream data transfers of 10 bytes or more
 Multiple MMC cards for the MMC communications protocol
 Only one SD or SDIO port can be used for SD or SDIO communications protocol
at one time.
 Up to two MMC or SD/SDIO cards when the SPI communications protocol is used.
Mixed card types are supported only by the SPI communications protocol.
3.3.10.2 MMC/SD/SDIO Controller Interface Signals
Table 27 MMC and SD/SDIO Mode Signals
CM-X300 Signal
Name
Type
Description
MMC_CLK
O
Bus clock
MMC_CMD0
I/O
Command and responses
MMC_CMD1
I/O
Command and responses
MMC_DAT[3:0]
I/O
Read and write data