Information

SDHC_BLKATTR field descriptions (continued)
Field Description
When restoring transfer content prior to issuing a resume command, the host driver shall restore the
previously saved block count.
NOTE: Although the BLKCNT field is 0 after reset, the read of reset value is 0x1. This is because when
XFERTYP[MSBSEL] bit is 0, indicating a single block transfer, the read value of BLKCNT is
always 1.
0000h Stop count
0001h 1 block
0002h 2 blocks
...
FFFFh 65535 blocks
15–13
Reserved
This read-only field is reserved and always has the value zero.
12–0
BLKSIZE
Transfer Block Size
This register specifies the block size for block data transfers. Values ranging from 1 byte up to the
maximum buffer size can be set. It can be accessed only when no transaction is executing (that is after a
transaction has stopped). Read operations during transfers may return an invalid value, and write
operations will be ignored.
000h No data transfer
001h 1 Byte
002h 2 Bytes
003h 3 Bytes
004h 4 Bytes
...
1FFh 511 Bytes
200h 512 Bytes
...
800h 2048 Bytes
...
1000h 4096 Bytes
49.4.3 Command Argument Register (SDHC_CMDARG)
This register contains the SD/MMC command argument.
Address: SDHC_CMDARG is 400B_1000h base + 8h offset = 400B_1008h
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
CMDARG
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Chapter 49 Secured digital host controller (SDHC)
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc. 1385