What is the recommended method to float GPIO pins when an SCB based component is stopped?

[GrCa_1363456]

For a PSoC 4 design...

While using SPI Master component (SPIM) to communicate with an external SPI Slave, I want the option to disable the SPI Master. I plan to switched the SPI Master function off using the SPIM_STOP().

After: SPIM_STOP(), what state will extenally connected pins be set to including: CS_N, SCLK, MOSI and MISO

These 4 lines are shared with other devices. If they don't automatically tri-state when the SPI Master component is stopped, can I force the pin into a tri-state mode directly or is there a better way to tri-state external pins driven by an SCB based component.

Greg

[BragadeeshV · Accepted solution]

Hi GrCa_1363456​,

The component takes care of SPI master output pins (CLK and SS) to the following  settings:

1. CLK is set to the inactive state settings based on CPOL in the configurator. CPOL: 0 - Set 0 ; CPOL :1 - Set 1

2. SS pin is set to the active high SS or active low SS setting in the configurator Active high- Set 0; Active low - Set 1

You can find the above information in SPI_SpiStop() in <SCB_name>_SPI.c

3. MOSI is set to strong drive

4. MISO is set to input pin (digital Hiz) - input buffer ON.

If you need to force them to analog HiZ, you can use the pin component APIs that is in the generated source.

You can set the drive mode using the API as shown above. Use 0 as the parameter to set it to analog Hiz.

Regards,

Bragadeesh