Information

46.4.23 MMC Boot Register (SDHC_MMCBOOT)
This register contains the MMC fast boot control register.
Address: SDHC_MMCBOOT is 400B_1000h base + C4h offset = 400B_10C4h
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R
BOOTBLKCNT
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
0
AUTOSABGEN
BOOTEN
BOOTMODE
BOOTACK
DTOCVACK
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
SDHC_MMCBOOT field descriptions
Field Description
31–16
BOOTBLKCNT
The value defines the stop at block gap value of automatic mode. When received card block cnt is equal
to BOOTBLKCNT and AUTOSABGEN is 1, then stop at block gap.
15–8
Reserved
This read-only field is reserved and always has the value zero.
7
AUTOSABGEN
When boot, enable auto stop at block gap function. This function will be triggered, and host will stop at
block gap when received card block cnt is equal to BOOTBLKCNT.
6
BOOTEN
Boot mode enable
0 Fast boot disable
1 Fast boot enable
5
BOOTMODE
Boot mode select
0 Normal boot
1 Alternative boot
4
BOOTACK
Boot ack mode select
0 No ack
1 Ack
3–0
DTOCVACK
Boot ACK time out counter value.
0000b SDCLK x 2^8
0001b SDCLK x 2^9
0010b SDCLK x 2^10
Table continues on the next page...
Memory map and register definition
K10 Sub-Family Reference Manual, Rev. 6, Nov 2011
1392 Freescale Semiconductor, Inc.