Does RMT loop implementation use Interrupt ?

[sanjuchopra]

I am experimenting with RMT peripheral. I like how flexible and extensible it is.
I wanted to know few things about its implementation in IDF v4.4.2.

When we enable loop_en in tx_config, does it use interrupt to resend the signals or DMA or its handled by RMT hardware ?
This information is important for me, if in case its using interrupt or any CPU cycle , I would like to optimize it.

[ESP_morris]

By hardware.