47.7.6.3 Connection Example

When more than one MCP3910 device is connected to the MCSPI, the SDO data lines from the MCP3910 products must be multiplexed prior to driving the MCSPI MOSI line.

The MCSPI offers two multiplexing capabilities (external or internal).

External Multiplexing mode

Multiplexing can be performed by successively enabling each SDO line from the MCP3910 with external discrete components (see the figure below).

In this mode, the four NPCS lines are activated successively after each frame reception.

The External Multiplexing mode is enabled by writing a 1 in the Chip Select Mode (CSM) bit in MCSPI_TPMR. The polarity of chip select output NPCS is defined by configuring the Chip Select Inversion Enable (CSIE) bit in MCSPI_MR.

Figure 47-17. External Multiplexing Mode Example

Example of Internal Multiplexing mode

Multiplexing is performed within the MCSPI. Each MOSI line is read successively.

To enable the Internal Multiplexing mode, the Multiple Input Line (MIL) bit must be set to ‘1’ in MCSPI_TPMR. The polarity of the MOSI lines can be defined by configuring the MOSI Inversion Enable (MOSIIE) bit in MCSPI_MR.

Figure 47-18. Internal Multiplexing Mode Example