Bus Speed Modes
Supported
Bus Modes Supported
Voltages
Supported
Max Data
Rate
(MBps)
Max Clock
Speed
(MHz)
Card Device
Type
High Speed
Default
Speed
8 bit
4 bit
1 bit
SPI
(30)
1.8 V
3.3 V
√
√
√
√
√
√
√
25
50
eMMC
SD/MMC Controller Block Diagram and System Integration
The SD/MMC controller includes a bus interface unit (BIU) and a card interface unit (CIU). The BIU
provides a slave interface for a host to access the control and status registers (CSRs). Additionally, this unit
also provides independent FIFO buffer access through a DMA interface. The DMA controller is responsible
for exchanging data between the system memory and FIFO buffer. The DMA registers are accessible by the
host to control the DMA operation. The CIU supports the SD, MMC, and CE-ATA protocols on the controller,
and provides clock management through the clock control block. The interrupt control block for generating
an interrupt connects to the generic interrupt controller in the ARM
®
Cortex
™
-A9 microprocessor unit
(MPU) subsystem.
Figure 11-1: SD/MMC Controller Connectivity
Slave
Interface
Master
Interface
MPU
Subsystem
Card Bus I/O Pins
FIFO
Buffer
Control
Synchronizer
Storage
FIFO Buffer
FIFO
Buffer
Control
Data Path
Control
Command
Path Control
Clock
Control
Interrupt
Control
DMA
Controller
Register
Block
Bus Interface Unit
Card Interface Unit
SD/MMC Controller
L4
Bus
L3
Interconnect
Functional Description of the SD/MMC Controller
This section describes the SD/MMC controller components and how the controller operates.
(30)
SPI mode is obsolete in the MMC 4.41 specification.
Altera Corporation
SD/MMC Controller
11-3
SD/MMC Controller Block Diagram and System Integration
cv_54011
2013.12.30