Intel® PXA255 Processor Developer’s Manual 15-27

MultiMediaCard Controller
15.5.6 MMC_RESTO Register (MMC_RESTO)

The MMC_RESTO, shown in Table15-10, controls the number of MMC clocks that the controller

must wait after the command before it can turn on the time-out error if a response has not occurr ed.

The default value of this register is 64.

This is a read/wri te register. Ignore reads from reserved bit s. Write zeros to res erved bits.
4STREAM_BL
OCK
Stream M ode
0 – Data transfer of the current command sequence is not in stream mode
1 – Data transfer of the current command sequence is in stream mode
3WRITE/READ
Read or Write Operation
0 – Specifies that the data transfer of the current command is a read operation
1 – Specifies that the data transfer of the current command is a write operation
2 DATA_EN Data Transfer Enable
0 – No data transfer with current command
1 – Specifies that the current command includes a data transfer
1:0 RESPONSE_
FORMAT[1:0]
These bits specify the response format for the current command.
00 – No response in MMC mode. Not supported in SPI mode
01 – Format R1, R1b, R4, and R5 in MMC mode. Format R1 and R1b in SPI mode
10 – Format R2 in MMC mode. Format R2 in SPI mode
11 – Format R3 in MMC mode. Format R3 in SPI mode

Table 15-9. MMC_CMDAT Bit Definitions (Sheet 2 of 2)

Physical Address
0x4110_0010 MMC_CMDAT Register MultiMediaCard Controller
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
MMC_DMA_EN
INIT
BUSY
STREAM_BLOCK
WRITE/READ
DATA_EN
RESPONSE_FORMAT[1:0]
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 1 0 0 0 0 0 0 0
Bits Name Description

Table 15-10. MMC_RESTO Bit Definitions

Physical Address
0x4110_0014 MMC_RESTO Register MultiMediaCard Controller
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 Number of MMC clocks before a response time-out