I leave the library to use ST7789 TFT display, I have translated one that is in C language. But unfortunately I have not been able to get it to work yet. I leave the files in case someone with more experience with these displays can review it.
If you are referring to the SPI bus it does not need pull-up resistors, and the only pull-up resistor I use is the MCLR pin bias resistor. If you don't use MCLR it is disabled in bit configuration. I was looking for a Pic18F46K20 at home but I don't have one to test.
I said in a previous thread.. When you are using an external MCLRE be wary that the pic NEVER hard boots if you keep the pickit 3 in place.. If you change the driver and then upload without removing power afterwards you only soft boot so "variables" are still intact, and then can give erroneous boots.
Thanks for the offer, but I've ordered two Pic18F46K22. Anyway, I recommend you go for the Pic18F46K22, which is very similar and has some of the internal modules duplicated. It also has something very important, and that is that it can work at 3.3 and 5v (1.8 to 5.5v), while the 46K20 only allows you to work at 3.3v (1.8 to 3.6v), at least in the versions I've seen.
Thanks for the offer, but I've ordered two Pic18F46K22. Anyway, I recommend you go for the Pic18F46K22, which is very similar and has some of the internal modules duplicated. It also has something very important, and that is that it can work at 3.3 and 5v (1.8 to 5.5v), while the 46K20 only allows you to work at 3.3v (1.8 to 3.6v), at least in the versions I've seen.