Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet
Product codes
AT32UC3A3-XPLD
852
32072H–AVR32–10/2012
AT32UC3A3
31.7.7
Block Register
Name: BLKR
Access Type: Read/Write
Offset: 0x018
Reset Value:
0x00000000
• BLKLEN: Data Block Length
This field determines the size of the data block.
This field is also accessible in the MR register.
If MR.FBYTE bit is zero, the BLKEN[17:16] field must be written to 0b00
Notes:
1. In SDIO Byte mode, BLKLEN field is not used.
2. BLKLEN should be specified before sending the data transfer command. Otherwise, Overrun
2. BLKLEN should be specified before sending the data transfer command. Otherwise, Overrun
may occur (even if MR.RDPROOF bit is set).
• BCNT: MMC/SDIO Block Count - SDIO Byte Count
This field determines the number of data byte(s) or block(s) to transfer.
The transfer data type and the authorized values for BCNT field are determined by CMDR.TRTYP field:
Warning: In SDIO Byte and Block modes, writing to the seven last bits of BCNT field is forbidden and may lead to unpredictable
results.
31
30
29
28
27
26
25
24
BLKLEN[15:8]
23
22
21
20
19
18
17
16
BLKLEN[7:0]
15
14
13
12
11
10
9
8
BCNT[15:8]
7
6
5
4
3
2
1
0
BCNT[7:0]
TRTYP
Type of Transfer
BCNT Authorized Values
0
MMC/SDCard Multiple Block
From 1 to 65535: Value 0 corresponds to an infinite block transfer.
2
SDIO Byte
From 1 to 512 bytes: Value 0 corresponds to a 512-byte transfer.
Values from 0x200 to 0xFFFF are forbidden.
3
SDIO Block
From 1 to 511 blocks: Value 0 corresponds to an infinite block transfer.
Values from 0x200 to 0xFFFF are forbidden.
Others
-
Reserved.