Maximum achievable I2C bus speed for nrf54lm20a?

[pertan]

Hi,

I'm wondering what the maximum achievable I2C bus speed is for the nrf54lm20a. The datasheet (v1.0) says

"Six TWI up to 400 kHz and I2C compatible (TWIM, TWIS)"

whereas this online lesson for the nrf54L-series says

"Variable bit rates – Supports 100 kbps, 400 kbps, and 1000 kbps bit rate depending on the selected pull-up resistor and bus capacitance combinations."

I've tried setting a bus speed of NRF_TWIM_FREQ_1000K but that only gives me an effective bus speed of 500k. 

Is 1000 kbps rate actually possible? If so, under what conditions?

Thanks

Edit: Forgot to mention that I'm using an early NRF54LM20_xxAA_ENGA engineering sample, if that matters.

Edit 2: I'm doing I2C communication from the FLPR core using the nrf_twim_* API. 

[Kenneth]

Hello,

Try with a 2.2kohm pull-up on SDA and SCL.

Kenneth

[pertan]

Changing the pull ups from 4.7k to 2.2k did the trick, thank you.