Public Version
www.ti.com
MMC/SD/SDIO Register Manual
Bits
Field Name
Description
Type
Reset
Read 0x0:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT4 line
(low).
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 0.
Write 0x0:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT4 line is driven low.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
Read 0x1:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT4 line
(high)
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 1.
Write 0x1:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT4 line is driven high.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
7
D3D
DAT3 input/output signal data value.
RW
0
Read 0x0:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT3 line
(low).
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 0.
Write 0x0:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT3 line is driven low.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
Read 0x1:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT3 line
(high)
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 1.
Write 0x1:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT3 line is driven high.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
6
D2D
DAT2 input/output signal data value.
RW
0
Read 0x0:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT2 line
(low).
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 0.
Write 0x0:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT2 line is driven low.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
Read 0x1:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT2 line
(high)
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 1.
Write 0x1:
If MMCi.
[3] DDIR bit = 0 (output
mode direction), the DAT2 line is driven high.
If MMCi.
[3] DDIR bit = 1 (input
mode direction), no effect.
5
D1D
DAT1 input/output signal data value.
RW
0
Read 0x0:
If MMCi.
[3] DDIR bit = 1 (input
mode direction), returns the value on the DAT1 line
(low).
If MMCi.
[3] DDIR bit = 0 (output
mode direction), returns 0.
3429
SWPU177N – December 2009 – Revised November 2010
MMC/SD/SDIO Card Interface
Copyright © 2009–2010, Texas Instruments Incorporated