AM335X SPI PINMUX config

Anson Yan

Hi，Ti employee

I have a new design use am335x，in the design，we want a spi with 2 cs，

SPI1_SCLK_MUX2,SPI1_D0_MUX2,SPI1_D1_MUX2,SPI1_CS0_MUX4 and

SPI1_SCLK_MUX2，SPI1_D0_MUX，2SPI1_D1_MUX2，SPI1_CS0_MUX2 are OK，

but SPI1_SCLK_MUX2，SPI1_D0_MUX2，SPI1_D1_MUX2，SPI1_CS0_MUX4，SPI1_CS0_MUX2 is IO set violation，is this not pre-defined IO Sets work？

As I know，the pinmux utility is not Complete， some IO set is OK，but not define in pinmux utility It make me puzzled !

over 12 years ago

0 peaves over 12 years ago

TI__Guru 62855 points

Many of the AM335x peripheral inputs and output signals were multiplexed to more than one device terminal as a way to reduce the limitations of pin-multiplexing. Multiplexing signals to multiple terminals adds a significant design complexity because each signal path needs to be properly timed with all other signals of the associated peripheral interface. If several signals of a peripheral interface can be multiplexed to multiple terminals, the number of possible combinations can be large. This makes it prohibitive to close timing on all possible combinations. Therefore, the AM335x does not support all possible combinations of pin-multiplexing. The supported combinations of pin-multiplexing for a specific peripheral interface are referred to as valid IO Sets.

The Pin Mux Utility provides a way to select valid IO Sets of specific peripheral interfaces to insure the pin-multiplexing configuration selected for a design only uses valid IO Sets supported by AM335x.

The Pin Mux Utility is the best way to determine if your application can be implemented with valid IO Sets. AM335x devices do not support pin mux configurations that do not use valid IO Sets.

Regards,
Paul