at91rm3400 ATMEL Corporation, at91rm3400 Datasheet - Page 379

• Manufacturer Part Number: at91rm3400
• Description: Atmel Advanced At91 Arm Microcontroller
• Manufacturer: ATMEL Corporation

Read Operation
Figure 159. Read Functional Flow Diagram
1790A–ATARM–11/03
Reset the PDCMODE bit
MCI_MR &= ~PDCMODE
Set the block length
MCI_MR |= (BlockLenght <<16)
Read status register MCI_SR
READ_SINGLE_BLOCK
Read data = MCI_RDR
Number words read =
BlockLength/4
Send command
RXRDY = 0?
Poll the bit
The following flowchart shows how to read a single block with or without use of PDC facilities.
In this example, a polling method is used to wait for the end of read. Similarly, the user can
configure the interrupt enable register (MCI_IER) to trigger an interrupt at the end of read.
These two methods can be applied for all MultiMediaCard read functions.
No
No
Send command SEL_DESEL_CARD
Send command SET_BLOCKLEN
Yes
to select the card
RETURN
Read with PDC
Configure the PDC channel
PDC_RPR = Data Buffer Address
PDC_RCR = BlockLength/4
PDC2_PTCR = PDC_RXTEN
Set the PDCMODE bit
MCI_MR |= PDCMODE
Set the block length
MCI_MR |= (BlockLength << 16)
Yes
Read status register MCI_SR
READ_SINGLE_BLOCK
Send command
ENDRX = 0?
RETURN
Poll the bit
No
AT91RM3400
Yes
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