Laptop User Manual

Intel® PXA26x Processor Family Developer’s Manual 15-27
MultiMediaCard Controller
15.5.7 MMC_RDTO Register
The MMC_RDTO register determines the length of time that the controller waits after a command
before it turns on the time-out error if data has not been received (see Table 15-12). The length of
time before a time-out occurs is measured in increments of 256 20-MHz periods and can be
calculated as follows:
It is the software’s responsibility to calculate the value for READ_TO. The default value is 0xffff,
which corresponds to 838.848 ms.
Table 15-11. MMC_RESTO Register
Physical Address
4110_0014
MMC_RESTO Register MMC
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
Reserved RES_TO
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 1 0 0 0 0 0 0
Bits Name Description
31:7 — Reserved
6:0 RES_TO
RESPONSE TIME-OUT:
Number of MMC clocks before a response time-out
Time-out Delay
MMC_RDTO[READ_TO]
()256()×
20MHz
-------------------- ------------------------------- -------------------------------- -------
MMC_RDTO[READ_TO]()128()×
10
7
--------------------- ------------------------------- -------------------------------- ------
sec==
Table 15-12. MMC_RDTO Register
Physical Address
4110_0018
MMC_RDTO Register MMC
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
Reserved READ_TO
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Bits Name Description
31:16 — Reserved
15:0 READ_TO
READ TIME-OUT:
Specifies the length of time before a data read time-out