NXP Semiconductors LPC43 Series User Manual

Contents

NXP Semiconductors LPC43 Series User Manual Manual pdf 449 page image

UM10503 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.User manual Rev. 1.3 — 6 July 2012 449 of 1269NXP Semiconductors UM10503Chapter 20: LPC43xx SD/MMC interface• Send STOP command - Can be sent on the command line while a data transfer is inprogress; this command can be sent at any time during a data transfer. Forinformation on sending this command, refer to "No-Data Command With or WithoutResponse Sequence".You can also use an additional setting for this command in order to set the Commandregister bits (5-0) to CMD12 and set bit 14 (stop_abort_cmd) to 1. If stopstop_abort_cmd is not set to 1, the user stopped a data transfer. Reset bit 13 of theCommand register (wait_prvdata_complete) to 0 in order to make the Module sendthe command at once, even though there is a data transfer in progress.– Send ABORT command - Can be used with only an SDIO_IOONLY orSDIO_COMBO card. To abort the function that is transferring data, program thefunction number in ASx bits (CCCR register of card, address 0x06, bits (0-2) usingCMD52.This is a non-data command. For information on sending this command, refer to"No-Data Command With or Without Response Sequence".Program the CMDARG register @0x28 with the appropriate command argumentparameters listed in Table 334.– Program the Command register using the command index as CMD52. Similar tothe STOPcommand, set bit 14 of the Command register (stop_abort_cmd) to 1,which must be done in order to inform the Module that the user aborted the datatransfer. Reset bit 13 (wait_prvdata_complete) of the Command register to 0 inorder to make the Module send the command at once, even though a data transferis in progress.– Wait for command_transfer_over.– Check response (R5) for errors.• During an open-ended card write operation, if the card clock is stopped because theFIFO is empty, the software must first fill the data into the FIFO and start the cardclock before issuing a stop/abort command to the card.20.7.5 Suspend or Resume SequenceIn an SDIO card, the data transfer between an I/O function and the Module can betemporarily halted using the SUSPEND command; this may be required in order toperform a high-priority data transfer with another function. When desired, the data transfercan be resumed using the RESUME command.Table 334. Parameters for CMDARG registerBits Contents Value31 R/W flag 130-28 Function number 0, for CCCR access27 RAW flag 1, if needed to read after write26 Don’t care -25-9 Register address 0x068 Don’t care -7-0 Write data Function number to be aborted