Texas Instruments AM335 Series Technical Reference Manual

www.ti.com Multimedia Card Registers
Table 18-38. SD_STAT Register Field Descriptions (continued)
Bit Field Type Reset Description
8 CIRQ R 0h Card interrupt.
This bit is only used for SD and SDIO cards.
In
1-bit mode, interrupt source is asynchronous (can be a source of
asynchronous wake-up).
In
4-bit mode, interrupt source is sampled during the interrupt cycle.
In CE-ATA mode, interrupt source is detected when the card drives
mmc_cmd line to zero during one cycle after data transmission end.
All modes above are fully exclusive.
The controller interrupt must be clear by setting SD_IE[8]
CIRQ_ENABLE to 0, then the host driver must start the interrupt
service with card (clearing card interrupt status) to remove card
interrupt source.
Otherwise the Controller interrupt will be reasserted as soon as
SD_IE[8] CIRQ_ENABLE is set to 1.
Writes to this bit are ignored.
0x0 = No card interrupt
0x1 = Generate card interrupt
7 CREM R/W 0h Card Removal.
This bit is set automatically when SD_PSTATE[CINS] changes from
1 to 0.
A clear of this bit doesn't affect Card inserted present state
(SD_PSTATE[CINS]).
0x0(W) = Status bit unchanged
0x0(R) = Card State stable or debouncing
0x1(W) = Status is cleared
0x1(R) = Card Removed
6 CINS R/W 0h Card Insertion.
This bit is set automatically when SD_PSTATE[CINS] changes from
0 to 1.
A clear of this bit doesn't affect Card inserted present state
(SD_PSTATE[CINS]).
0x0(W) = Status bit unchanged
0x0(R) = Card State stable or debouncing
0x1(W) = Status is cleared.
0x1(R) = Card inserted
5 BRR R/W 0h Buffer read ready.
This bit is set automatically during a read operation to the card (see
class
2 - block oriented read commands) when one block specified by the
SD_BLK
[10:0] BLEN bit field is completely written in the buffer.
It indicates that the memory card has filled out the buffer and that the
local host needs to empty the buffer by reading it.
Note: If the DMA receive-mode is enabled, this bit is never set
instead a DMA receive request to the main DMA controller of the
system is generated.
0x0(W) = Status bit unchanged
0x0(R) = Not ready to read buffer
0x1(W) = Status is cleared.
0x1(R) = Ready to read buffer
3427
SPRUH73H–October 2011–Revised April 2013 Multimedia Card (MMC)
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Texas Instruments AM335 Series Specifications

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Brand	Texas Instruments
Model	AM335 Series
Category	Computer Hardware
Language	English