51.12.10 SDMMC Host Control 1 Register (SD_SDIO)
Name: | SDMMC_HC1R (SD_SDIO) |
Offset: | 0x28 |
Reset: | 0x00 |
Property: | Read/Write |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
CARDDSEL | CARDDTL | DMASEL[1:0] | HSEN | DW | LEDCTRL | ||||
Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | ||
Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bit 7 – CARDDSEL Card Detect Signal Selection
This bit selects the source for the card detection.
Value | Description |
---|---|
0 |
The SDMMC_CD pin is selected. |
1 |
The Card Detect Test Level (CARDDTL) is selected (for test purposes). |
Bit 6 – CARDDTL Card Detect Test Level
This bit is enabled while the Card Detect Signal Selection (CARDDSEL) is set to 1 and it indicates whether the card is inserted or not.
Value | Description |
---|---|
0 | No card. |
1 | Card inserted. |
Bits 4:3 – DMASEL[1:0] DMA Select
One of the supported DMA modes can be selected. The DMA modes supported are given in SDMMC_CA0R. Use of a selected DMA is determined by DMA Enable (DMAEN) in SDMMC_TMR.
Value | Name | Description |
---|---|---|
0 | SDMA | SDMA is selected |
1 | – | Reserved |
2 | ADMA32 | 32-bit Address ADMA2 is selected |
3 | – |
Reserved |
Bit 2 – HSEN High Speed Enable
Before setting this bit, the user must check High Speed Support (HSSUP) in SDMMC_CA0R.
If this bit is set to 0 (default), the SDMMC outputs CMD line and DAT lines at the falling edge of the SD clock (up to 25 MHz). If this bit is set to 1, the SDMMC outputs the CMD line and the DAT lines at the rising edge of the SD clock (up to 50 MHz).
If Preset Value Enable (PVALEN) in SDMMC_HC2R is set to 1, the user needs to reset SD Clock Enable (SDCLKEN) before changing this bit to avoid generating clock glitches. After setting this bit to 1, the user sets SDCLEN to 1 again.
Value | Description |
---|---|
0 | Normal Speed mode. |
1 | High Speed mode. |
Bit 1 – DW Data Width
This bit selects the data width of the SDMMC. It must be set to match the data width of the card.
0 (1_BIT): 1-bit mode.
1 (4_BIT): 4-bit mode.
Bit 0 – LEDCTRL LED Control
This bit is used to caution the user not to remove the card while it is being accessed. If the software is going to issue multiple commands, this bit is set to 1 during all transactions.
0 (OFF): LED off.
1 (ON): LED on.