2 mci mode register – Rainbow Electronics AT91CAP9S250A User Manual
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6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
41.10.2
MCI Mode Register
Name: MCI_MR
Access Type: Read/write
• CLKDIV: Clock Divider
Multimedia Card Interface clock (MCCK or MCI_CK) is Master Clock (MCK) divided by (2*(CLKDIV+1)).
• PWSDIV: Power Saving Divider
Multimedia Card Interface clock is divided by 2
(PWSDIV)
+ 1 when entering Power Saving Mode.
Warning: This value must be different from 0 before enabling the Power Save Mode in the MCI_CR (MCI_PWSEN bit).
• RDPROOF Read Proof Enable
Enabling Read Proof allows to stop the MCI Clock during read access if the internal FIFO is full. This will guarantee data
integrity, not bandwidth.
0 = Disables Read Proof.
1 = Enables Read Proof.
• WRPROOF Write Proof Enable
Enabling Write Proof allows to stop the MCI Clock during write access if the internal FIFO is full. This will guarantee data
integrity, not bandwidth.
0 = Disables Write Proof.
1 = Enables Write Proof.
• PDCFBYTE: PDC Force Byte Transfer
Enabling PDC Force Byte Transfer allows the PDC to manage with internal byte transfers, so that transfer of blocks with a
size different from modulo 4 can be supported.
Warning: BLKLEN value depends on PDCFBYTE.
0 = Disables PDC Force Byte Transfer. PDC type of transfer are in words.
1 = Enables PDC Force Byte Transfer. PDC type of transfer are in bytes.
• PDCPADV: PDC Padding Value
0 = 0x00 value is used when padding data in write transfer (not only PDC transfer).
1 = 0xFF value is used when padding data in write transfer (not only PDC transfer).
• PDCMODE: PDC-oriented Mode
0 = Disables PDC transfer
1 = Enables PDC transfer. In this case, UNRE and OVRE flags in the MCI Mode Register (MCI_SR) are deactivated after
the PDC transfer has been completed.
• BLKLEN: Data Block Length
This field determines the size of the data block.
This field is also accessible in the MCI Block Register (MCI_BLKR).
Bits 16 and 17 must be set to 0 if PDCFBYTE is disabled.
Note:
In SDIO Byte mode, BLKLEN field is not used.
31
30
29
28
27
26
25
24
BLKLEN
23
22
21
20
19
18
17
16
BLKLEN
15
14
13
12
11
10
9
8
PDCMODE
PDCPADV
PDCFBYTE
WRPROOF
RDPROOF
PWSDIV
7
6
5
4
3
2
1
0
CLKDIV