ST STEVAL-PCC009V2, User Manual

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Running the IBU UI tool UM0935
18/53 Doc ID 17398 Rev 3
Then, provide values, to read and write from the slave device, to the tool. Data to be written
should be provided in the hex format. After every read or write operation, the tool provides
the status (e.g. status: communication complete/bus free) so that the status of the I
2
C
communication taking place between the IBU UI board and the I
2
C slave daughter board
can be checked. Please note that the number of bytes to be written should be non-zero and
in decimal format.
The status messages are of the following types depending on the communication that has
taken place:
● Communication complete/bus free
●
Wrong acknowledge failure/connection errors
● I
2
C timeout that occurs when the slave device does not respond for a predefined
interval of time
●
Other reasons: this occurs when the user tries to perform read/write operations with a
data length equal to zero.
Also, there is a communication status LED D1 available on the board. It lights up whenever
there is any type of communication error of type 2), 3), or 4) above. The LED status is
updated after each read or write operation.
The transfer sequence for one byte of I
2
C is shown in Figure 12 .
Figure 12. Transfer sequence of one byte of I
2
C
Therefore this interface allows any I
2
C interface based slave device to be connected and
tested.
3.2 Using the SPI interface of the 10-pin connector
To use the SPI interface, it must be selected by sending the command from the DLL, as
mentioned in the DLL help file. After this, the board is ready to be used in SPI mode. The
section below explains how the tool and its features behave once selection has been made
using the DLLs and it also explains how the hardware setup is to be done.
Figure 13 below
shows the interpretation of the 10-pin header when it is configured in SPI mode.