15-36 Intel® PXA255 Processor Developer’s Manual
MultiMediaCard Controller
15.5.16 MMC_RES FIFO
MMC_RES FIFO, shown in Table 15-21, contains the response after a command. It is 16 bits wide
by eight entries.The RES FIFO does not contain the 7-bit CRC for the response. The status for
CRC checking and response time-out status is in the status register, MMC_STAT.
The first half-word read from the response FIFO is the most significant half-word of the received
response.
This is a read-only register. Ignore reads from reserved bits.
15.5.17 MMC_RXFIFO FIFO
MMC_RXFIFO, shown in Table 15-22, consists of two dual FIFOs, where each FIFO is eight bits
wide by 32 entries deep. This FIFO holds the data read from a card. It is a read only FIFO to the
software, and is read on 8-bit boundaries. The eight bits of data are read on a 32-bit boundary and
occupying the least significant byte lane (7:0).
This is a read-only register. Ignore reads from reserved bits.
Table 15-21. MMC_RES, FIFO Entry
Physical Address
0x4110_003c
MMC_RES FIFO Entry 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 RESPONSE_DATA
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 x x x x x x x x x x x x x x x x
Bits Name Description
31:16 — reserved
15:0
RESPONSE_
DATA
Two bytes of response data
Table 15-22. MMC_RXFIFO, FIFO Entry
Physical Address
0x4110_0040
MMC_RXFIFO Entry 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 READ_DATA
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 x x x x x x x x
Bits Name Description
31:8 — reserved
7:0 READ_DATA One byte of read data