DISCLAIMER: if this kind of thing triggers you, please press ALT-F4 before commenting. Negative people really make this forum suck some times. If that's you, please quietly move on and ignore this. Tribalism, racism, or nationalistic bias is not welcome either. I am not a Microchip attorney, don't care if you are, or if you spend Saturday nights with cheerleader pom poms for their attorneys.
In case anyone has not heard of the LGT8F328 a Chinese company makes AVR clones with silicon hardware mods (12b diff ADC/8b DAC/32MHz/etc.). LGT claims to have 49 instructions that take less clock cycles than the ATmega. It has 3 omitted instructions and 4 new instructions. It also has 88 new registers that the ATmega has listed as Reserved on the datasheet.
Logic Green are not pursuing a Western market, but there are options available from China Direct sources. You won't be able to get them through traditional, or even Western facing Chinese distribution companies. There are several boards available from various China direct sources though, and some of these places list chips as well.
The chip really needs some better documentation in English, there is nothing available officially. They have a working Arduino tool chain with a few examples. They also have their own SDK program, programmer, and (IIRC) an IAR example setup. Unfortunately they haven't done the Arduino tool chain with a proper AVRdude implementation. They did everything inside the awkward Arduino (as) ISP interface and inside of the Arduino IDE's makefile system. There are calls to AVRdude in the makefile but there isn't a serperate -C config-file that can be used external to the Arduino environment. This is one of the things I would really like. We are currently limited to using an Arduino optiboot bootloader only.
You can find out more from a guide and collection of info here:
https://github.com/dbuezas/lgt8fx.
I've been playing around with the documentation but I'm getting in a bit over my head. I've posted a few things on github but it isn't complete, just a casual work in progress. I've spent the last day looking for detailed info about the ATmega's AVR core architecture, and trying to compare it to the LGT's, but I'm quickly realizing how little information has actually been disclosed about things like the ALU of the ATmega.
I probably need to post pages of the PDF so I can get some feedback about corrections and a little help. There are a few English translated datasheets floating around. I have 4 different ones so far. They are all very bad. I'm not saying I can make a good one, I don't even speak Chinese. However, I can format the Chinese text so that a translation program can do a proper job line by line. No translation program appears to be able to retain proper word formatting on a 267 page PDF and they really suck at putting the text back where it belongs. Perhaps someone with the time to create the PDF could do a better job with the help of a community?
My goal is to make this match the Chinese document page for page with text recognition and an index table. The first page is marketing fluff so that can be used for notes. My current 1st page will change. I have pages 2-12 edited and posted along with a couple spreadsheets comparing the instruction sets and registers. I'm doing all of this with free software and saving all the files publicly so anyone could edit and revise my work.
https://github.com/Upcycle-Electronics/LGT8Fx-Datasheet/tree/master/finalpdf