we measured i2c2(7000c400) signal, but it had many glitch, we delete all peripherals by the bus on the hardware and software, but is still the question. The attached picture is the glitch signal.
Hi, please support, we had a demo borad but we cann’t make it to work, so I wonder if your boards have this problem ? we had delete all peripherals, it just high level and it still had glitch.
We are checking will update once get result.
During this time could you check other i2c if the same
Thanks
We don’t see this on devkit. Please check your I2C power supply design including pull-ups and also the pinmux setting and etc. Also please share more info and tests you have done so that we can help to analyze more.
i2c2: i2c@7000c400 {
#address-cells = <1>;
#size-cells = <0>;
compatible = “nvidia,tegra210-i2c”;
reg = <0x0 0x7000c400 0x0 0x100>;
interrupts = <0 84 0x04>;
iommus = <&smmu TEGRA_SWGROUP_PPCS>;
status = “disabled”;
clock-frequency = <400000>;
dmas = <&apbdma 22>, <&apbdma 22>;
dma-names = “rx”, “tx”;
clocks = <&tegra_car TEGRA210_CLK_I2C2>, <&tegra_car TEGRA210_CLK_PLL_P>;
clock-names = “div-clk”, “parent”;
resets = <&tegra_car 54>;
reset-names = “i2c”;
};
It is I2C2, other i2c bus is OK, just I2C2 had glitch.
So no device on I2C2 bus, right? And so can you see same glitch on VDD_1.8V? And have you remove the pull-ups to check if glitch still on 1.8V? What tests have you done?
Why the status is disable?
we disable i2c2 bus peripherals in dts,and remove peripherals on hardware.
we just found i2c2 bus glitch, it is 3.3V, the pull-ups is DNP.
Did you verify by enable?
So no device on I2C2 bus, right?
Yes.
And so can you see same glitch on VDD_1.8V? And have you remove the pull-ups to check if glitch still on 1.8V? What tests have you done?
I2C2 bus is 3.3V ,the pull-ups is DNP， other I2C bus didn’t find glitch.
Yes, we found the problem when the peripherals enable on i2c2 bus, so we disable them, then it still had glitch.
What’s “disable them”? Don’t you remove the device? Can you try that so that let the I2C pins unconnected to any device? Can you ask your hardware engineer to do more basic tests?
I means: on hardware, we had disconnected add devices, on software, we had disable DTS configs.
Do you mean I2C2 or GEN2_I2C? Per your picture, the prior is 1.8V pull-up, the latter is 3.3V. Have you probe the 3.3V/1.8V power rail to check if this glitch exists?
I2C2 == GEN2_I2C, “the prior is 1.8V pull-up, the latter is 3.3V” ? Isn’t GEN2_I2C 3.3V?
As you can see in picture, GEN2_I2C is 3.3V, I2C2 is 1.8V.
Have you probe the 3.3V power rail to check if this glitch exists? Which means the 3.3V end of the pull-up resistor.
The I2C2 is the in code name, It corresponds to GEN2_I2C on hardware picture. And from the picture, GEN2_I2C didn’t connect to VDD_3V3_SYS, from our hardware colleagues,
GEN2_I2C is pull-up by nvidia module internal circuit. So we wonder if it is a SOC problem?
There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Thanks
The 3.3V to GEN2 and GEN1 is same, can you see glitch on GEN1 port?
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