ADSP-BF50x Blackfin Processor Hardware Reference
21-17
Removable Storage Interface
Like the commands, all responses are sent on the
RSI_CMD
signal.
A response always has a “0” start bit followed by a “0” transmission bit
to indicate the transfer is from card to host. Unlike the commands issued
by the host, not all responses are protected by a CRC7 checksum. Refer
to the appropriate specification for full details on the response formats and
whether they are protected by a CRC7 checksum.
When a short response is received, the response is broken down by the RSI
and the 32-bit field containing bits 39:8 of the 48-bit response is stored to
RSI_RESPONSE0
, where bit 39 of the response corresponds to bit 31 of
RSI_RESPONSE0
and bit 8 of the response to bit 0 of
RSI_RESPONSE0
. Bits
45:40 of the response are stored to the
RESP_CMD
field of the
RSI_RESP_CMD
register.
For a long response, bits 127:1 of the response are stored in
RSI_RESPONE0–3
, where bit 31 of
RSI_RESPONSE0
contains the most
significant bit (bit 127) of the response and bit 0 of
RSI_RESPONSE3
contains bit 1 of the response. Bit 31 of
RSI_RESPONSE3
is always zero.
Figure 21-3
shows the command path state machine. In order for the state
machine to be active, the RSI must be enabled via
RSI_CLK_EN
. Disabling
the clocks to the RSI will result in the state machine returning to the
IDLE state. The command path state machine is responsible for setting
and clearing a number of status flags within the
RSI_STATUS
register (see
“RSI Status Register (RSI_STATUS)” on page 21-65
).
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...