RT1062 timestamping clock (ts_clk)

[zt]

As part of a PTP implementation, on the RT1062, I would like to change the timestamping clock from 25MHz to 100MHz.

The reference manual IMXRT1060RM Rev 2, 12/2019 page 2137 section 41.6.94 "Time-Stamping Clock Period Register" mentions the clock period of the timestamping clock in the INC field.

However, I can not find where I can set the source frequency for the this clock.
It is currently set to 25MHz, which appears to be the same as the Ethernet clock. Are the two clocks one and the same?

My question: How can I change the frequency of the timestamping clock?

[zt]

Thank you Kerry, for your prompt reply.

The code snippet you included sets up the Ethernet clock to be 50MHz, which is as expected.

However, I am interested in having the PTP 1588 timestamping clock run at 100MHz. 
When I change the .loopDivider from 1 to 2, for example, the Ethernet interface is no longer correctly initialised.

It seems to me that the Ethernet clock and the timestamping clock are linked when they should be independent of each other - am I correct?

There is a missing piece to this puzzle.

[kerryzhou]

Hi @zt ,

 My understand is, if the enableClkOutput25M is enabled, the PTP clock is 25M.

And the 50Mhz output clock is output to the PHY, if you set it to 100Mhz, then the output 100Mhz to the PHY, but your PHY is fixed to use 50Mhz.

This is my understanding, you also can check the RM related register in my above picture.

Best Regards,

kerry

[kerryzhou · Accepted solution]

Hi @zt 

This code is used to configure the timestamping clock:

void BOARD_InitModuleClock(void)
{
/* Set 50MHz output clock required by PHY, set PTP clock 25MHz. */
const clock_enet_pll_config_t config = {.enableClkOutput = true, .enableClkOutput25M = true, .loopDivider = 1};
CLOCK_InitEnetPll(&config);

/* Output 50MHz clock to PHY. */
IOMUXC_EnableMode(IOMUXC_GPR, kIOMUXC_GPR_ENET1TxClkOutputDir, true);
}

25Mhz.

Wish it helps you!

Best Regards,

Kerry