Texas Instruments TMS320DM644x Benutzerhandbuch
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4.4
MMC Status Register 1 (MMCST1)
Registers
The MMC status register 1 (MMCST1) records specific events or errors. There are no interrupts
associated with these events or errors.
associated with these events or errors.
The MMC status register 1 (MMCST1) is shown in
and described in
.
Figure 21. MMC Status Register 1 (MMCST1)
31
16
Reserved
R-0
15
8
Reserved
R-0
7
6
5
4
3
2
1
0
Reserved
FIFOFUL
FIFOEMP
DAT3ST
DRFUL
DXEMP
CLKSTP
BUSY
R-0
R-0
R-0
R-0
R-0
R-0
R-1
R-0
LEGEND: R = Read only; -n = value after reset
Table 9. MMC Status Register 1 (MMCST1) Field Descriptions
Bit
Field
Value
Description
31-7
Reserved
0
Reserved
6
FIFOFUL
FIFO is full.
0
FIFO is not full.
1
FIFO is full.
5
FIFOEMP
FIFO is empty.
0
FIFO is not empty.
1
FIFO is empty.
4
DAT3ST
DAT3 status.
0
The signal level on the DAT3 pin is a logic-low level.
1
The signal level on the DAT3 pin is a logic-high level.
3
DRFUL
Data receive register (MMCDRR) is full.
0
A data receive register full condition is not detected. The data receive shift register is not full.
1
A data receive register full condition is detected. The data receive shift register is full. No new bits can
be shifted in from the memory card.
be shifted in from the memory card.
2
DXEMP
Data transmit register (MMCDXR) is empty.
0
A data transmit register empty condition is not detected. The data transmit shift register is not empty.
1
A data transmit register empty condition is detected. The data transmit shift register is empty. No bits
are available to be shifted out to the memory card.
are available to be shifted out to the memory card.
1
CLKSTP
Clock stop status.
0
CLK is active. The memory clock signal is being driven on the pin.
1
CLK is held low because of a manual stop (CLKEN = 0 in MMCCLK), receive shift register is full, or
transmit shift register is empty.
transmit shift register is empty.
0
BUSY
Busy.
0
No busy signal is detected.
1
A busy signal is detected (the memory card is busy).
SPRUE30B – September 2006
Multimedia Card (MMC)/Secure Digital (SD) Card Controller
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