Information

Overview
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
Freescale Semiconductor 1-17
audio and video consumer electronic devices. The physical form factor, pin assignments, and data
transfer protocol are forward-compatible with the old MMC.
•SDIO
Under the SD protocol, the SD cards can be categorized as a memory card, I/O card, or combo card.
The memory card invokes a copyright protection mechanism that complies with the security of the
SDMI standard. The I/O card provides high-speed data I/O with low power consumption for
mobile electronic devices. The combo card has both memory and I/O functions.
The eSDHC acts as a bridge, passing host bus transactions to SD/SDIO/MMC cards by sending commands
and performing data accesses to or from the cards. It handles the SD/SDIO/MMC protocol at the
transmission level.
The eSDHC can select the following modes for data transfer:
• SD 1-bit
• SD 4-bit
• MMC 1-bit
• MMC 4-bit
• Identification mode (up to 400 KHz)
• Full-speed mode (up to 25 MHz) or high-speed mode (up to 50 MHz)
1.2.13 System Timers
The system includes the following timers:
• Periodic interrupt timer
• Real time clock
• Software watchdog timer
• One general-purpose timer block, supporting four 16-bit programmable timers or two cascaded
32-bit timers, or one cascaded 64-bit counter