User guide
Redpine Signals, Inc. Proprietary and Confidential. Page 106
R
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9
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1
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0
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-
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N
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1
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1
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2
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5
0 1 0 1 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 1 0
0
0 0 0 0 0 0 0 0 0 1 0 1 1 0 0 0 0 1 0 1 1 0 0 0
C1 (0x54)
C2 (0x40) C3 (0x12)
Status Response for C1 (0x58)
sclk
cs
data in to
SPI slave
(RSI module)
0 0 0 0 0 0 0 0
C4 (0x00)
A0,A1,A2,A3
Misc Data
0 1 0 1 1 0 0 0
Variable
Wait Period
Start Token
(0x0000_0055)
Valid Data
(with 32-bit granularity)
sclk
cs
Dummy
data out from
SPI slave
(RS module)
data in to
SPI slave
(RSI module)
data out from
SPI slave
(RS module)
Status Response for C2 (0x58)
Status Response for C3 (0x58)
0 1 0 1 1 0 0 0
Status Response for C4 (0x58)
.......
Status
Response
for address bytes
.......
.......
Figure 22: Memory Read
The following is the procedure to be followed by the Host to do a memory read.
1. Prepare and send the commands C1, C2 as described for Master
read.
2. Read the response from the SPI slave (RS9110-N-11-2X module).
3. Status 0x58 indicates that the slave is ready. Host should next
send the commands C3, C4, which indicate the length of the data
to be read, followed by the address of the memory location to be
read.
4. After sending/receiving C3, C4 commands/response and the
addresses, the Host should wait for a start token (0x55). Host
writes a stream of dummy bytes to read the data from the module
each time. The Host should read this data until the start token is
received. The data following the start token should be interpreted
as the frame of specified length that is read from the slave.
5. Status 0x54, after C1 and C2 bytes, indicates that the device is
busy. Host has to retry.
6. Status 0x52, after C1 and C2 bytes, indicates a failure response
from the slave.
There is a variable wait period, during which dummy data is sent. After this
period, a start token is transmitted from the slave to the master. The start token
is followed by valid data. The start token indicates to the Host the beginning of
valid data. To read out the valid data, dummy data [D0, D1, D2, …. D(N-1)] is
sent. N is the number of bytes to be read.
The commands C1, C2, C3 and C4 are sent in the following sequence (explained
in Bit ordering of SPI transmission/reception) : C1 first, then C2, C3 and finally
C4. The bit ordering is