TMS320DM644x DMSoC Multimedia Card (MMC)/Secure Digital (SD) Card Controller User's Guide

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4.16 MMC Data Response Register (MMCDRSP)
4.17 MMC Command Index Register (MMCCIDX)
Registers
After the MMC controller sends a data block to a memory card, the return byte from the memory card is
stored in the MMC data response register (MMCDRSP).
The MMC data response register (MMCDRSP) is shown in Figure 37 and described in Table 23 .
Figure 37. MMC Data Response Register (MMCDRSP)
31 16
Reserved
R-0
15 8 7 0
Reserved DRSP
R-0 R/W-0
LEGEND: R/W = Read/Write; R = Read only; - n = value after reset
Table 23. MMC Data Response Register (MMCDRSP) Field Descriptions
Bit Field Value Description
31-8 Reserved 0 Reserved
7-0 DRSP 0-FFh During a write operation (see Section 2.3.1 ), the CRC status token is stored in DRSP.
The MMC command index register (MMCCIDX) stores the first byte of a response from a memory card.
Table 21 and Table 22 show the format for each type of response.
The MMC command index register (MMCCIDX) is shown in Figure 38 and described in Table 24 .
Figure 38. MMC Command Index Register (MMCCIDX)
31 16
Reserved
R-0
15 8 7 6 5 0
Reserved STRT XMIT CIDX
R-0 R/W-0 R/W-0 R/W-0
LEGEND: R/W = Read/Write; R = Read only; - n = value after reset
Table 24. MMC Command Index Register (MMCCIDX) Field Descriptions
Bit Field Value Description
31-8 Reserved 0 Reserved
7 STRT 0-1 Start bit. When the MMC controller receives a response, the start bit is stored in STRT.
6 XMIT 0-1 Transmission bit. When the MMC controller receives a response, the transmission bit is stored in XMIT.
5-0 CIDX 0-3Fh Command index. When the MMC controller receives a response, the command index is stored in CIDX.
SPRUE30B – September 2006 Multimedia Card (MMC)/Secure Digital (SD) Card Controller 57
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