SIM5218E Hardware Design
good ESD performance, some ESD components should be added beside the SD/MMC card holder.
The following features are implemented:
■
Supports 4-bit SD, 1-bit SD, and 1-bit MMC interface
■
SW-configurable edge latching (falling or rising)
■
SW-configurable data and command values change (rising or falling edge)
■
Clock-gating for power saving (and a power-saving option to always turn the clock off
when bus is idle)
■
Flow control option to prevent overflow and underflow
■
SD_CLK output up to 25 MHz
Following figure illustrate and describe the MMC/SD interface.
Figure 27
：
MMC/SD interface
As mentioned, the MMC/SD interface supports SD according to the SD physical layer
specification 2.0, up to 4-bit data mode. It is also capable of supporting 1-bit MMC according to
MCC specification 3.31. While the same hardware controller is used, the initialization for SD
cards and MMCs are different. SIM5218E will auto-detect which card is inserted (SD or MMC, or
no card) and will proceed accordingly.
Table 25:
MMC/SD pin of SIM5218E
voltage scope( V )
Name
Direction
Pin
(On board-to-board connector)
Min
Type
Max
SD_DATA0
Input /Output
36
2.7
2.85
3.0
SD_DATA1
Input /Output
37
2.7
2.85
3.0
SD_DATA2
Input /Output
38
2.7
2.85
3.0
SD_DATA3
Input /Output
39
2.7
2.85
3.0
SD_CLK
Output
34
2.7
2.85
3.0
SD_CMD
Output
35
2.7
2.85
3.0
SIM5218E_ Hardware Design_V1.06
2012.09.21
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Содержание SimCom SIM5218E
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