Registers
1315
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Multimedia Card (MMC)/Secure Digital (SD) Card Controller
26.4.18 SDIO Control Register (SDIOCTL)
The SDIO control register (SDIOCTL) is shown in
and described in
Figure 26-38. SDIO Control Register (SDIOCTL)
31
16
Reserved
R-0
15
2
1
0
Reserved
RDWTCR
RDWTRQ
R-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 26-25. SDIO Control Register (SDIOCTL) Field Descriptions
Bit
Field
Value
Description
31-2
Reserved
0
Reserved
1
RDWTCR
Read wait enable for CRC error. To end the read wait operation, write 0 to RDWTRQ. (No need to clear
RDWTCR).
0
Read wait is disabled.
1
Automatically start read wait on CRC error detection during multiple block read access and not the last
block to be transferred. RDWTRQ is automatically set to 1.
0
RDWTRQ
Read wait request. To end the read wait operation, write 0 to RDWTRQ.
0
End read wait operation and release MMCSD_DAT2.
1
Set a read wait request. Read wait operation starts 2 clocks after the end of the read data block.
MMCIF asserts low level on MMCSD_DAT2 until RDWTRQ is cleared to 0.