Add MEGA65 hardware support

amb5l / tyto2

The Tyto Project - version 2

GNU Lesser General Public License v3.0

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Add MEGA65 hardware support #4

Open amb5l opened 1 year ago

amb5l commented 1 year ago

Further to this issue with the old repo, let's add the MEGA65 as a supported platform for the hdmi_tpg design (and bring in the oserdese2 related fix).

@sy2002 How many revisions of the MEGA65 hardware do I need to consider? TE0765-03.pdf is rev 03?

sy2002 commented 1 year ago

@amb5l Let's only consider "Revision 3" aka R3 for now. Reason:

Revision 1 was only a test-board
Revision 2 used an ADV7511 to generate the HDMI signal. Back in the days, I was not close enough to the project to really understand why Paul and Deft shelved the idea of using the ADV7511. Only 20 MEGA65 R2 were produced.
Revision 3 "DevKit" and Revision 3A "The MEGA65" are quite identical (minor changes such as a larger core flash memory in R3A) - so in the MEGA65 community the R3 and R3A are not really distinguished and just called "R3".

The R3 MEGA65s are using your code.

amb5l commented 1 year ago

Understood. I am now working on this. I have ordered a MEGA65 from Trenz - should have done this long ago!

The ADV7511 will have consumed many I/O pins (about the same number as for VGA => VDAC) and will have been significantly more expensive than driving TMDS directly.

sy2002 commented 1 year ago

Hey cool that you ordered a MEGA65 :-) But here comes the bad news: You will probably need to wait until Christmas 2023 to get it due to "Global Chip Crisis". I recommend to join the MEGA65 discord (invitation link is in the other issue) and watch the #order-support channel there to learn more about the exact delivery date.

And thanks for your thoughts around the ADV7511.

amb5l commented 1 year ago

Take a look at this commit. You will find a bitstream (hdmi_tpg_mega65r3.bit) in build/hdmi_tpg/hdmi_tpg_mega65r3. At the moment this uses the joystick fire buttons - A to step the mode and B to reset. I will look at how to use the keyboard.