AM2434: PRUs running at different frequencies?

Hi Mohan,

The AM2434 device allows for independent clock source selection for its two PRU_ICSSG instances, which provides flexibility in how they are clocked.

Each ICSSG subsystem (ICSSG0 and ICSSG1) features its own CTRLMMR_ICSSGn_CLKSEL register, which allows you to independently select the CORE_CLK source for that specific instance 1. For each instance, you can choose between MAIN_PLL2_HSDIV0_CLKOUT or MAIN_PLL0_HSDIV9_CLKOUT as the clock source 1. Additionally, each PRU_ICSSG core can be configured to use a synchronous ICSSGn_ICLK (at 250 MHz) instead of the selectable CORE_CLK 1, 1.

While you have independent control over the source selection for each instance, please note that the maximum operating frequency for the PRU_ICSSG modules on the AM243x family is 333 MHz 2. Because the available clock sources are derived from the system PLLs, the specific frequencies you can achieve for each instance will depend on the configuration of those common PLLs.

1. AM64x/AM243x Technical Reference Manual
2. PRU-ICSSG Industrial Ethernet Reference Design