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Secure digital input/output interface (SDIO)
Full name and abbreviation description of terms
Table 111 Full name and abbreviation description of terms
Full name in English
English abbreviation
First Input First Output
FIFO
Command Path State Machine
CPSM
Data Path State Machine
DPSM
Introduction
The secure digital input/output interface can connect SD card, SD I/O card,
multi-media card (MMC) and CE-ATA card master interfaces, and provide data
transmission between APB2 system bus and SD memory card, SD I/O card,
MMC and CE-ATA device.
Main characteristics
SD card: Compatible with SD memory card specification version 2.0
SD I/O card: Compatible with SD I/O card specification version 2.0:
support two different bus modes: 1 bit (default) and four bits.
MMC: Compatible with multimedia card system specification 4.2 and
previous versions. Three different data bus modes are supported:1 bit
(default), 4 bits and 8 bits.
CE-ATA: Compatible with CE-ATA digital protocol version 1.1.
The data transmission rate in 8-bit bus mode is up to 48MHz
Interrupt and DMA request
Data and command output enable signal, used for controlling
bidirectional driver.
Note: SDIO of current version only supports one SD/SD IO/MMC 4.2 card at the same time, however, it
supports multiple MMC4.1 or cards of previous version.
Functional description
SDIO structure mainly contains two parts:
SDIO adapter: Realize the related functions of MMC/SD/SD I/O cards, and
consist of control unit, data unit and command unit. The control unit manages