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MM516
User's Manual
28
Revision 1.4 7-8-2011
Hardware Description Manual
5.3.2 Writing to the Device
To write to BlueCore 5 chip, the 8-bit write command (00000010) is sent first (C[7:0]) followed by a 16-bit address (A[15:0]).
The next 16-bits (D[15:0]) clocked in on SPI_MOSI are
written to the location set by the address (A). Thereafter for each subsequent 16-bits clocked in, the address (A) is
incremented and the data written to consecutive locations until the transaction terminates when SPI_CSB is taken
high.
Figure 10 SPI Write Operation
5.3.3 Reading from the Device
Reading from BlueCore 5 chip is similar to writing to it. An 8-bit read command (00000011) is sent first (C[7:0]),
followed by the address of the location to be read (A[15:0]).BlueCore 5 chip then outputs
on SPI_MISO a check word during T[15:0] followed by the 16-bit contents of the addressed location during bits
D[15:0].
The check word is composed of {command, address [15:8]}. The check word may be used to confirm a read operation
to a memory location. This overcomes the problems encountered with typical serial peripheral interface slaves,
whereby it is impossible to determine whether the data returned by a read operation is valid data or the result of the
slave device not responding.
If SPI_CSB is kept low, data from consecutive locations is read out on SPI_MISO for each subsequent 16 clocks,
until the transaction terminates when SPI_CSB is taken high.
Figure 11 SPI Read Operation