MMC/SD Host Controller
7-150
This register is used to configure the SPI interface and start an SPI transfer
if SPI mode has been enabled.
Table 7–110. MMC SPI Configuration Register (MMC_SPI)
Bit
Name
Description
15
Start
Start SPI transfer
14
WnR
Write/not read
13 –12
Reserved
11 –10
TCSH
Chip-select hold time control
9 –8
TCSS
Chip-select setup time control
7 –6
Reserved
5 –4
CS
Chip-select control
3
CSM
Chip-select mode
2
CSD
Chip-select disable
1
PHA
Phase control
0
POL
Polarity control
Start SPI Transfer (Start)
This set-only bit (15) always reads as 0. A write to 0 has no effect.
When set to 1 by the local host, a SPI transfer is automatically started.
Note:
The user must take care to initialize MMC_BLEN:BLEN before starting an
SPI transfer.
SPI transfer automatically stops when the size programmed in
MMC_BLEN:BLEN decrements down to 0 (in read and in write).
-
0: No action
-
1: SPI transfer started
Value after reset is low.