AM2432: Clock Setting without CTT

Hi Mari,

Mari Tsunoda said:

My customer is trying to set up their own clocks.

Which clocks? Are these clocks accessible from Sysconfig?

Ideally this shouldn't be required, please see: https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/08_02_00_31/exports/docs/api_guide_am243x/DRIVERS_SOC_PAGE.html#autotoc_md630

"Most of these APIs are already integrated with SysConfig tool and the generated code does the required call to enable a module, set the required clock and so on. User need to use these APIs in their application only for exceptional scenarios."

If at all possible, I strongly suggest your customer use Sysconfig for managing the clocks.

Mari Tsunoda said:

They looked at a sample project in the EVM

Which example?

Mari Tsunoda said:

They see that there are two API calls, one for activating the clock (SOC_moduleClockEnable) and another for setting the clock (SOC_moduleSetClockFrequency).

It also seems like the the clock is first activated, then the clock is set

Your understanding is correct.

Clocks are managed by SYSFW executing on DMSC. The SOC API functions internally call Sciclient driver API functions, please see: https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/08_02_00_31/exports/docs/api_guide_am243x/DRIVERS_SCICLIENT_PAGE.html

Sciclient driver API functions request SYSFW (via TISCI) to enable clocks and set clock frequencies.

Mari Tsunoda said:

could you tell us what the relationship between moduleId and clockId is?

The module and clock IDs are assigned by TISCI, and are used for communicating with SYSFW (i.e. so SYSFW understands the requests for clock configuration). The clock IDs are "local" IDs to a specific module.

To understand what each clock ID means for a specific module, you'll need to consult the AM64x/AM243x TRM (spruim2).

You can also consult the TISCI docs: https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am64x/clocks.html#

Taking the UART for example:

            ti_power_clock_config.c:
                uint32_t gSocModules[] = {
                    TISCI_DEV_UART0,

                    SOC_MODULES_END,
                };

                SOC_ModuleClockFrequency gSocModulesClockFrequency[] = {
                    { TISCI_DEV_UART0, TISCI_DEV_UART0_FCLK_CLK, 96000000 },

                    { SOC_MODULES_END, SOC_MODULES_END, SOC_MODULES_END },
                };

<SDK>/source/drivers/sciclient/include/tisci/am64x_am243x/tisci_devices.h:

#define TISCI_DEV_UART0 146

<SDK>/source/drivers/sciclient/include/tisci/am64x_am243x/tisci_clocks.h:

                #define TISCI_DEV_UART0_FCLK_CLK 0
                #define TISCI_DEV_UART0_FCLK_CLK_PARENT_USART_PROGRAMMABLE_CLOCK_DIVIDER_OUT0 1
                #define TISCI_DEV_UART0_FCLK_CLK_PARENT_HSDIV4_16FFT_MAIN_1_HSDIVOUT1_CLK 2
                #define TISCI_DEV_UART0_VBUSP_CLK 3

In TRM, Figure 12-258. UART[0-6] Integration

The TISCI clock ID macros correspond to the clocks I've highlighted in yellow.

Regards,
Frank

Hi Mari,

Mari Tsunoda said:

They have been looking at SysConfig, but I see that you can't set all the clocks as listed in https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/am64x/clocks.html

In case certain clocks aren't covered by Sysconfig, they'd use the SOC API:

• https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/08_02_00_31/exports/docs/api_guide_am243x/DRIVERS_SOC_PAGE.html
• https://software-dl.ti.com/mcu-plus-sdk/esd/AM243X/08_02_00_31/exports/docs/api_guide_am243x/group__DRV__SOC__MODULE.html

Mari Tsunoda said:

My understanding is that you can set these separately via the API? Would this be correct?

Correct.

Mari Tsunoda said:

Would you also be able to tell me where I can find the default clock frequencies for each? Is there some document that lists this? I don't see any information like this on the link above.

I'm unaware of such a document.

There is a GEL script which can be executed from R5F_0_0 to obtain all the PLL and clock divider settings. In CCS, connect to R5F_0_0 and execute: Scripts->PLL Configuration->Get PLL Configurations->Get_All_PLL_Configurations. It takes a little work to interpret script output and they'll probably need to consult the TRM Section 5.4 Clocking. Obviously a script could be written to interpret the output of this GEL script to automatically determine the clock frequencies.

Regards,
Frank