Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet

SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

910

 HS

MCI_BLKR

0x40000018

 Read

/Write  

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 the TRTYP field in the HSMCI Com-

mand Register (HSMCI_CMDR).
When TRTYP = 1 (MMC/SDCARD Multiple Block), BCNT can be programmed from 1 to 65535, 0 corresponds to an infi-

nite block transfer. 
When TRTYP = 4 (SDIO Byte), BCNT can be programmed from 1 to 511, 0 corresponds to 512-byte transfer. Values in 

range 512 to 65536 are forbidden.
When TRTYP = 5 (SDIO Block), BCNT can be programmed from 1 to 511, 0 corresponds to an infinite block transfer. Val-

ues in range 512 to 65536 are forbidden.

 In SDIO Byte and Block modes (TRTYP = 4 or 5), writing the 7 last bits of BCNT field with a value which differs 

from 0 is forbidden and may lead to unpredictable results.

This field determines the size of the data block. 
Bits 16 and 17 must be set to 0 if FBYTE 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

BCNT

7

6

5

4

3

2

1

0

BCNT