UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
298 of 362
NXP Semiconductors
UM10208
Chapter 23: LPC2800 SD/MMC
5.6 Command Response Register (MCIRespCommand - 0x8010 0010)
The read-only MCIRespCommand register contains the command index field of the last
command response received.
shows the MCIRespCommand register.
If the command response transmission does not contain the command index field (long
response), the RespCmd field is unknown, although it must contain 111111 (the value of
the reserved field from the response).
5.7 Response Registers (MCIResponse0-3 - 0x8010 0014, 018, 01C, 020)
The read-only MCIResponse0-3 registers contain the status of a card, which is part of the
received response.
shows the MCIResponse0-3 registers.
The card status size can be 32 or 127 bits, depending on the response type (see
The most significant bit of the card status is received first. The MCIResponse3 register
LSBit is always 0.
5.8 Data Timer Register (MCIDataTimer - 0x8010 0024)
The MCIDataTimer register contains the data timeout period, in card bus clock periods.
shows the MCIDataTimer register.
A counter loads the value from the data timer register, and starts decrementing when the
Data Path State Machine (DPSM) enters the WAIT_R or BUSY state. If the timer reaches
0 while the DPSM is in either of these states, the timeout status flag is set.
A data transfer must be written to the data timer register and the data length register
before being written to the data control register.
Table 337. Command Response register (MCIRespCommand - 0x8010 0010)
Bit
Symbol
Description
Reset
Value
5:0
RespCmd
Response command index
0
31:6
-
Reserved. The value read from a reserved bit is not defined.
-
Table 338. Response registers (MCIResponse0-3 -es 0x8010 0014, 0x8010 0018,
0x8010 001C, 0x8010 0020)
Bit
Symbol
Description
Reset Value
31:0 Status
Card status
0x0000 0000
Table 339. Response Register Type
Description
Short Response
Long Response
MCIResponse0
Card status [31:0]
Card status [127:96]
MCIResponse1
Unused
Card status [95:64]
MCIResponse2
Unused
Card status [63:32]
MCIResponse3
Unused
Card status [31:1]
Table 340. Data Timer register (MCIDataTimer - 0x8010 0024)
Bit
Symbol
Description
Reset Value
31:0
DataTime
Data timeout period.
0x0000 0000