Hello Aiden,
let me clarify the various UART options on the AM243x device first.
Following UARTs are possible:
1. Standard UART on the device which has driver in SDK. This is limited to 10 MHz and does not have real-time trigger which is needed for motor application.
2. ICSS_G hardware UART which was initially brought into ICSS_G IP for low latency 12 Mbit Profibus communication
3. PRU software UART which uses PRU GPIO to emulate UART. This was typically used on older devices (AM335x) to get additional standard UART.
4. ICSS_G 3 peripheral interface can be used to implement serial interfaces including UART, known encoder protocols (HDSL, ENDAT, Tamagawa, BISS) or custom serial interface with line code. It supports time triggered start and higher data rates e.g. 25 Mbit.
As you are asking for 6 UARTs I recommend to use 3 peripheral interface which is available on each slice of one ICSS_G instance. There is also a SDK example with Tamagawa Interface using 3 peripheral interface as UART.
Pin mapping is described in AM243x TRM Table 6-422. PRU GPI/GPO Signals and Configurations for Peripheral I/F.
Note that there is also an alternative pin mapping shown in Table 6-391. PRU_ICSSG<k> I/O Signals and controlled by ICSSG_SA_MX_REG[7] G_MUX_EN register. You cannot mix signals from both settings.
Here is a example pin assignment for 6 UARTs on ICSS_G0 using default pin mapping with G_MUX_EN=0.
- Thomas
