search

rkrajnc / minimig-mist

Minimig for the MiST board
GNU General Public License v3.0
63 stars 40 forks source link

Timing fixes #87

Closed gyurco closed 5 years ago

gyurco commented 5 years ago

These should fix the timing issues

rkrajnc commented 5 years ago

Hi,

thanks for the pull req. I'll try to merge this and test it today or tomorrow.

Were the changes tested in any way? I honestly don't remember how I came up with the constraints, and can't tell if this would work better or not. Also, is the increased drive strength for the SDRAM necessary?

The user_io change definitely looks good.

gyurco commented 5 years ago

I've played with various games, the core looks stable for me. TimeQuest report is definitely much better. I get a warning if the SDRAM_CLK is not 8mA for reduced max frequency, but probably it doesn't hurt if the other signals can be stronger (would need to check the datasheet for max. input currents...). I did it all of the cores updated by me, nothing broke since that. The 4/3 multicycle path in the TG68k deals with the 114MHz clock, it worked well in the Genesis core, too, until it was switched to FX68K.

rkrajnc commented 5 years ago

Hmmm,

looks like emulation of joystick / mouse on keyboard isn't working anymore, I'll have to check if these changes are responsible, or is this something that already happened before.