ST7789 Datasheet,

st789SDS-PAGEnative PAGE TrisTris base2-Amino-2-(hydroxymethyl)-1,3-propanediolC 4 H 11 NO 3 121.14>99.9%Snificantly optimized for 16MHz AVR Arduino boards (2.5-5x faster than other libraries). Achieved 6.9Mbps SPI transfer rate (at DIV216MHz clock) In compatiliblity mode it could work with other MCUs, but I didn't test it.