Multimedia Card Registers
Table 18-38. SD_STAT Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
18
CEB
R/W
0h
Command end bit error.
This bit is set automatically when detecting a 0 at the end bit position
of a command response.
0x0(W) = Status bit unchanged
0x0(R) = No error
0x1(W) = Status is cleared.
0x1(R) = Command end bit error
17
CCRC
R/W
0h
Command CRC error.
This bit is set automatically when there is a CRC7 error in the
command response depending on the enable bit (SD_CMD[19]
CCCE).
0x0(W) = Status bit unchanged
0x0(R) = No error
0x1(W) = Status is cleared.
0x1(R) = Command CRC error
16
CTO
R/W
0h
Command timeout error.
This bit is set automatically when no response is received within 64
clock cycles from the end bit of the command.
For commands that reply within 5 clock cycles - the timeout is still
detected at 64 clock cycles.
0x0(W) = Status bit unchanged
0x0(R) = No error
0x1(W) = Status is cleared.
0x1(R) = Time Out
15
ERRI
R
0h
Error interrupt.
If any of the bits in the Error Interrupt Status register (SD_STAT
[31:16]) are set, then this bit is set to 1.
Therefore the host driver can efficiently test for an error by checking
this bit first.
Writes to this bit are ignored.
0x0 = No interrupt
0x1 = Error interrupt event(s) occurred
14-11
Reserved
R
0h
10
BSR
R/W
0h
Boot Status Received Interrupt.
This bit is set automatically when SD_CON[BOOT] is set 1 or 2 and
a boot status is received on DAT[0] line.
This interrupt is only useful for MMC card.
0x0(W) = Status bit unchanged
0x0(R) = No interrupt
0x1(W) = Status is cleared.
0x1(R) = Boot Status Received Interrupt occurred.
9
OBI
R
0h
Out-of-band interrupt (This interrupt is only useful for MMC card).
This bit is set automatically when SD_CON[14] OBIE bit is set and
an out-of-band interrupt occurs on OBI pin.
The interrupt detection depends on polarity controlled by
SD_CON[13] OBIP bit.
The out-of-band interrupt signal is a system specific feature for future
use, this signal is not required for existing specification
implementation.
0x0(W) = Status bit unchanged
0x0 = No out-of-band interrupt
0x1(W) = Status is cleared.
0x1 = Interrupt out-of-band occurs
3426
Multimedia Card (MMC)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated