UM1685 datasheet(29/31 Pages) STMICROELECTRONICS

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UM1685

Daisy chaining

More demonstration boards can be connected in daisy chain mode.

To drive two or more boards in daisy chain configuration:

Connect the STEVAL-PCC009V2 board 10-pin connector to the SPI_IN connector of

the first demonstration board through the 10-pole flat cable.

Open the termination jumper (see Section 1.1: EVAL6480H on page 5 and Section 1.2:

EVAL6482H on page 14).

Connect the SPI_OUT connector of the first demonstration board to the SPI_IN of the

next one through the 10-pole flat cable.

Repeat point 2 and 3 for all the others board of the chain but the last one.

Check the termination jumpers of the demonstration boards: all the jumpers but the last

one should be opened.

Note:

Increasing the number of devices connected in chain could degrade SPI communication

performances. If communication issues occur, try to reduce the SPI clock speed.

Table 13. VDD supply configurations

Configuration

JP5

JP6

VDD range

Notes

Supplied by VREG

Closed

Open

3.3 V

Default, 3.3 V logic.

Supplied by SPI

connectors

Open

Closed

3.3 V or 5 V

3.3 V when connected to the STEVAL-PCC009V2

Supplied by VDD test

point

Open

3.3 V or 5 V

Must be 3.3 V if connected to the STEVAL-PCC009V2

UM1685 Datasheet(PDF) 29 Page - STMicroelectronics