NXP Semiconductors LPC24XX UM10237 - Manual (Page 569)

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User manual Rev. 04 — 26 August 2009 569 of 792
NXP Semiconductors
UM10237
Chapter 21: LPC24XX SD/MMC card interface
Note: This register should be read only when the data transfer is complete.
6.11 Status Register (MCIStatus - 0xE008 C034)
The MCIStatus register is a read-only register. It contains two types of flag:
• Static [10:0]: These remain asserted until they are cleared by writing to the Clear
register (see
Section 21–6.12 “Clear Register (MCIClear - 0xE008 C038)” ).
• Dynamic [21:11]: These change state depending on the state of the underlying logic
(for example, FIFO full and empty flags are asserted and deasserted as data while
written to the FIFO).
Table 21–504 shows the bit assignment of the MCIStatus register.
Table 503: Data Counter register (MCIDataCnt - address 0xE008 C030) bit description
Bit Symbol Description Reset
Value
15:0 DataCount Remaining data 0x0000
31:16 - Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined. NA
Table 504: Status register (MCIStatus - address 0xE008 C034) bit description
Bit Symbol Description Reset
Value
0 CmdCrcFail Command response received (CRC check failed). 0
1 DataCrcFail Data block sent/received (CRC check failed). 0
2 CmdTimeOut Command response timeout. 0
3 DataTimeOut Data timeout. 0
4 TxUnderrun Transmit FIFO underrun error. 0
5 RxOverrun Receive FIFO overrun error. 0
6 CmdRespEnd Command response received (CRC check passed). 0
7 CmdSent Command sent (no response required). 0
8 DataEnd Data end (data counter is zero). 0
9 StartBitErr Start bit not detected on all data signals in wide bus mode. 0
10 DataBlockEnd Data block sent/received (CRC check passed). 0
11 CmdActive Command transfer in progress. 0
12 TxActive Data transmit in progress. 0
13 RxActive Data receive in progress. 0
14 TxFifoHalfEmpty Transmit FIFO half empty. 0
15 RxFifoHalfFull Receive FIFO half full. 0
16 TxFifoFull Transmit FIFO full. 0
17 RxFifoFull Receive FIFO full. 0
18 TxFifoEmpty Transmit FIFO empty. 0
19 RxFifoEmpty Receive FIFO empty. 0