UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
576 of 1441
NXP Semiconductors
UM10503
Chapter 22: LPC43xx/LPC43Sxx SD/MMC interface
22.7.4.8 Stream Read
A stream read is like the block read mentioned in "Single-Block or Multiple-Block Read",
except for the following bits in the Command register:
transfer_mode = 1; //Stream transfer
cmd_index = CMD20;
A stream transfer is allowed for only a single-bit bus width.
22.7.4.9 Stream Write
A stream write is exactly like the block write mentioned in "Single-Block or Multiple-Block
Write", except for the following bits in the Command register:
•
transfer_mode = 1;//Stream transfer
•
cmd_index = CMD11;
In a stream transfer, if the byte count is 0, then the software must send the STOP
command. If the byte count is not 0, then when a given number of bytes completes a
transfer, the Module sends the STOP command. Completion of this AUTO_STOP
command is reflected by the Auto_command_done interrupt. A response to an
AUTO_STOP is stored in the RESP1 register @0x34.
A stream transfer is allowed for only a single-bit bus width.
22.7.4.10 Sending Stop or Abort in Middle of Transfer
The STOP command can terminate a data transfer between a memory card and the
Module, while the ABORT command can terminate an I/O data transfer for only the
SDIO_IOONLY and SDIO_COMBO cards.
User-selectable
Wait_prvdata_complete
1
Before sending command on
command line, cpu should wait for
completion of any data command in
process, if any (recommended to
always set this bit, unless the current
command is to query status or stop
data transfer when transfer is in
progress)
Check_response_crc
1
0 – Do not check response CRC
1 – Check response CRC
Some of command responses do not
return valid CRC bits. Software should
disable CRC checks for those
commands in order to disable CRC
checking by controller.
Table 394. CMD register settings for Single-block or Multiple-block write
Name
Value
Comments