MMU OC BOARD

[exxos]

A branch from troed's thread here about overclocking the MMU...

https://www.exxosforum.co.uk/forum/viewt ... f=18&t=283


I brought some SMT MMU's for this, why ? because they had the latest production run date on them, so I am going to assume they will overclock better than the vast production ranges of the PLCC MMU..


First problem to address is the SMT MMU will not easily fit on top of the PLCC MMU.

mmu.JPG

Secondly, I want to add DRAM onto this board as well. So this will likely cause some major routing issues.. :roll:

As I already have the DRAM boards already made and tested, it would be more cost-effective to use these as a add-on option for this MMU adapter board..

So what I am thinking, is have one PCB which will solder into the PLCC MMU motherboard pads, and basically become a breakout board which will be larger than the MMU. So should give space to add the existing DRAM board basically over the top of the SMT MMU.

It will require to PCBs I think to do this, so I need to think about this a little more. But the least the PCBs would be relatively small and it will greatly speed up the project if I do not have to basically design another DRAM board when I already have some constructed...

[exxos]

A first play.. going with tiny tracks..

mmu2.JPG

Will see if I can get someone to do a layout to fit my 4 MB RAM boards.. Idea that it would solder in over the top of the SMT MMU...

Will do all routing on 2 layers, and 2 more layers for solid 5V and 0V...

I also need to split some lines to this... Though I am half wondering that as troed got it working a single GAL, of adding the GAL onto this board as its a prototype... Ultimately the GAL will be in my main booster GAL, but will need solder pads on this MMU board anyway...