Multimedia Card Registers
Table 18-35. SD_PSTATE Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
18
CDPL
R
0h
Card Detect Pin Level.
MMC/SD/SDIO1 only.
SDIO cards only.
This bit reflects the inverse value of the card detect input pin
(SDCD).
Debouncing is not performed on this bit and is valid only when Card
State is stable.
(SD_PSTATE[17] is set to 1).
This bit must be debounced by software.
The value of this register after reset depends on the card detect
input pin (SDCD) level at that time.
0x0 = The value of the card detect input pin (SDCD) is 1.
0x1 = The value of the card detect input pin (SDCD) is 0.
17
CSS
R
0h
Card State Stable.
This bit is used for testing.
It is set to 1 only when Card Detect Pin Level is stable
(SD_PSTATE[18] CPDL).
Debouncing is performed on the card detect input pin (SDCD) to
detect card stability.
This bit is not affected by software reset.
0x0 = Reset or Debouncing.
0x1 = Reset or Debouncing.
16
CINS
R
0h
Card inserted.
This bit is the debounced value of the card detect input pin (SDCD).
An inactive to active transition of the card detect input pin (SDCD)
will generate a card insertion interrupt (SD_STAT[CINS]).
A active to inactive transition of the card detect input pin (SDCD) will
generate a card removal interrupt (SD_STAT[REM]).
This bit is not affected by a software reset.
0x0 = If SD_CON[CDP] is cleared to 0 (default), no card is detected.
The card may have been removed from the card slot. If
SD_CON[CDP] is set to 1, the card has been inserted.
0x1 = If SD_CON[CDP] is cleared to 0 (default), the card has been
inserted from the card slot. If SD_CON[CDP] is set to 1, no card is
detected. The card may have been removed from the card slot.
15-12
Reserved
R
0h
11
BRE
R
0h
Buffer read enable.
This bit is used for non-DMA read transfers.
It indicates that a complete block specified by SD_BLK
[10:0] BLEN bits has been written in the buffer and is ready to be
read.
It is cleared to 0 when the entire block is read from the buffer.
It is set to 1 when a block data is ready in the buffer and generates
the Buffer read ready status of interrupt (SD_STAT[5] BRR bit).
0x0 = Read BLEN bytes disable
0x1 = Read BLEN bytes enable. Readable data exists in the buffer.
10
BWE
R
0h
Buffer Write enable.
This status is used for non-DMA write transfers.
It indicates if space is available for write data.
0x0 = There is no room left in the buffer to write BLEN bytes of data.
0x1 = There is enough space in the buffer to write BLEN bytes of
data.
9
RTA
R
0h
Read transfer active.
This status is used for detecting completion of a read transfer.
It is set to 1 after the end bit of read command or by activating a
continue request (SD_HCTL[17] CR bit) following a stop at block gap
request.
This bit is cleared to 0 when all data have been read by the local
host after last block or after a stop at block gap request.
0x0 = No valid data on the mmc_dat lines.
0x1 = Read data transfer on going.
3417
SPRUH73H – October 2011 – Revised April 2013
Multimedia Card (MMC)
Copyright © 2011–2013, Texas Instruments Incorporated