Multimedia Card Registers
Table 18-38. SD_STAT Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
4
BWR
R/W
0h
Buffer write ready.
This bit is set automatically during a write operation to the card (see
class
4 - block oriented write command) when the host can write a
complete block as specified by SD_BLK
[10:0] BLEN.
It indicates that the memory card has emptied one block from the
buffer and that the local host is able to write one block of data into
the buffer.
Note: If the DMA transmit mode is enabled, this bit is never set
instead, a DMA transmit request to the main DMA controller of the
system is generated.
0x0(W) = Status bit unchanged
0x0(R) = Not ready to write buffer
0x1(W) = Status is cleared.
0x1(R) = Ready to write buffer
3
DMA
R/W
0h
DMA Interrupt.
This status is set when an interrupt is required in the ADMA
instruction and after the data transfer completion.
0x0(W) = Status bit unchanged
0x0(R) = DMA Interrupt detected
0x1(W) = Status is cleared.
0x1(R) = No DMA Interrupt
2
BGE
R/W
0h
Block gap event.
When a stop at block gap is requested (SD_HCTL[16] SBGR bit),
this bit is automatically set when transaction is stopped at the block
gap during a read or write operation.
0x0(W) = Status bit unchanged
0x0(R) = No block gap event
0x1(W) = Status is cleared
0x1(R) = Transaction stopped at block gap
1
TC
R/W
0h
Transfer completed.
This bit is always set when a read/write transfer is completed or
between two blocks when the transfer is stopped due to a stop at
block gap request (SD_HCTL[16] SBGR bit).
0x0(W) = Status bit unchanged
0x0(R) = No transfer complete
0x1(W) = Status is cleared
0x1(R) = Data transfer complete
0
CC
R/W
0h
Command complete.
This bit is set when a
1-to-0 transition occurs in the register command inhibit
(SD_PSTATE[0] CMDI bit)
0x0(W) = Status bit unchanged
0x0(R) = No command complete
0x1(W) = Status is cleared
0x1(R) = Command complete
3428
Multimedia Card (MMC)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated