Kontron COMe-mSP1 Instrukcja Użytkownika Pobierz pdf (Strona 44)

COMe-mSP1 / Features and Interfaces

4.17 SDIO

The SD card standard is a standard for removable memory storages designed and licensed by the SD Card Association

(http://sdcard.org). The card form factor, electrical interface, and protocol are all part of the SD Card specification. The

Intel® System Controller Hub US15W supports up to 3 SDIO interfaces. On nanoETXexpress-SP the first interface SDIO#0

(4-bit wide) is shared with the module GPIO signals. The integrated SDIO 1.1/MMC 4.1 controller in US15W only supports

byte-address mode for SDIO storage cards up to 2GB. Sector-addressing and SDHC is not supported.

» MMC 4.1 transfer rates can be up to 48MHz and bus widths of 1, 4 or 8 bits

» SDIO 1.1 supports transfer rates up to 24MHz and bus widths of 1 or 4 bits

The following table shows which GPIO-ports can be used for the SD-card interface:

General purpose Input/output SD card interface signals

GPI0 SLOT0_DATA0

GPI1 SLOT0_DATA1

GPI2 SLOT0_DATA2

GPI3 SLOT0_DATA3

GPO0 SLOT0_CLK

GPO1 SLOT0_CMD

GPO2 SLOT0_WP

GPO3 SLOT0_CD#

The SD_CMD line needs a pull-up resistor that can vary depending on the length of the

electrical paths (typical from 10kOhm to 100kOhm).

The maximum length for SDIO signals on the baseboard should be 80mm.

1 2 ... 39 40 41 42 43 44 45 46 47 48 49 ... 96 97

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