Added by foft over 7 years ago. Updated over 7 years ago.
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Description
The whole system is clocked at 32*original clock. However the 6502 turbo is limited to 16x due to the ram speed, since a block ram access cycle takes 2 cycles. Try to clock the block ram at 64* original clock as a quick win to get 32x turbo working.
Trying simply feeding in the clock at twice the speed to see if it passes timing!
I have something working on the simulator - alone. Now need to plug it into the core proper to see if it works. Will probably need some clever timequest rules too, since the read/write deadlines are different now.
Nope, this is not going to be so simple... Massive timing violations.
So thinking about options...
Double the main clock speed and pipeline a bit
or
Output next address from antic and the cpu, so I can read the memory 1 cycle earlier - antic clearly knows what it will read, does the 6502 core?
or
Add a cache?!
I enabled 32x mode in the core and sorted out single cycle writes from the block ram for now. Hardly any difference in sysinfo but good to see at least some difference.