AM2634: Is SYS_CLK always 200MHz?

Andy MacGregor

Part Number: AM2634

Hi, I want to write a function that converts from SYS_CLK ticks to time. I see in a few places in the TRM that the default frequency of SYS_CLK is 200MHz, but I'd like this function to always work regardless of clock configuration.

Can I always assume that AM263x SYS_CLK frequency is 200MHz? Or is there an MCU+SDK API function that will return the current SYS_CLK value (I couldn't find one)?

Thank you,

-Andy

over 1 year ago

0 Akshit Pareek over 1 year ago

TI__Expert 4230 points

Hi Andy,

The clock configuration is located in two places. One is in GELs, and the other one is in SBL. One of these methods is needed to configure the clock.
Please refer to https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1211814/am2631-am263x-syscfg and AM2634: Is the system clock frequency fixed? How do I configure the PLL to generate clocks for each peripheral? for more information.

CLKSRCSEL and CLKINUSE Registers can be checked to get the CLK source and its frequency respectively.

#include <stdio.h>
#include <kernel/dpl/DebugP.h>
#include <drivers/hw_include/cslr_soc.h>
#include <drivers/soc.h>
#include <drivers/soc/am263x/soc_rcm.c>

uint32_t base = CSL_TOP_RCM_U_BASE;

static inline void
App_readAndPrintRegValue()
{
    // clksrcsel
    uint32_t r5ssClkSrcSel;
    r5ssClkSrcSel = HW_RD_REG32(base + CSL_TOP_RCM_R5SS_CLK_SRC_SEL) & CSL_TOP_RCM_R5SS_CLK_SRC_SEL_CLKSRCSEL_MASK;
    DebugP_log("CSL_TOP_RCM_R5SS_CLK_SRC_SEL: 0x%x\r\n", r5ssClkSrcSel);

    // clkinuse
    uint32_t r5ssClkStatus;
    r5ssClkStatus = HW_RD_REG32(base + CSL_TOP_RCM_R5SS_CLK_STATUS) & CSL_TOP_RCM_R5SS_CLK_STATUS_CLKINUSE_MASK;
    DebugP_log("CSL_TOP_RCM_R5SS_CLK_STATUS: 0x%x\r\n", r5ssClkStatus);
}

Regards,
Akshit

0 Andy MacGregor over 1 year ago in reply to Akshit Pareek

Intellectual 257 points

Hi, I think my question wasn't clear enough. I am not looking to configure SYS_CLK.

I am working with the ESM which is clocked by SYS_CLK directly. I'm referring to the diagram at
"6.4.3.3 IP Clocks working on SYS_CLK" in the reference manual on its clock structure. Is this SYS_CLK always 200MHz with valid clock configuration? If not, how can I calculate the SYS_CLK frequency in hertz given the values read from the CLKSRCSEL and CLKINUSE?

+1 Akshit Pareek over 1 year ago in reply to Andy MacGregor

TI__Expert 4230 points

    enum SOC_RcmPeripheralClockSource_e clkSrc = SOC_RcmPeripheralClockSource_SYS_CLK;

    uint32_t clkFreq = SOC_rcmGetPeripheralClockFrequency(clkSrc);

    DebugP_log("Clock Frequency: %u\r\n", clkFreq);

If it's clocked with SYS_CLK directly, you can use the above code to get the Clock Frequency.

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AM2634: Is SYS_CLK always 200MHz?