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Author Topic: Interfacing 8 bit wide EPROM to 68060?  (Read 2036 times)

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Offline fiat1100dTopic starter

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Interfacing 8 bit wide EPROM to 68060?
« on: January 10, 2008, 11:01:29 AM »
Is it possible to directly interface an EPROM with bus width of 8 bit to the 68060 or the fact that 68060 doesn't support "dynamic bus sizing" would be an issue?
 

Offline fiat1100dTopic starter

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Re: Interfacing 8 bit wide EPROM to 68060?
« Reply #1 on: January 10, 2008, 12:02:57 PM »
But when accessing the memory location where I need to put that EPROM, that is F00000 (hex) for having the code executed at boot time, will the 68060 know to make 8 bit reads or it will try to read 32-bit wide?
By reading the 68060 manual, I see that SIZx pins are to be used, together with A0 and A1, to select a byte in a 32-bit word... While for having 8 bit transfers I would need to connect A0 and A1 directly to the EPROM so that an increase by 1 of the address bus effectively points to the following memory location.
 

Offline fiat1100dTopic starter

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Re: Interfacing 8 bit wide EPROM to 68060?
« Reply #2 on: January 10, 2008, 01:53:02 PM »
So I would have to modify all word and long word instructions of the code I have with byte ones, plus making some quite complex PLD...

For starting then maybe it is better if I try with 2 x 16 bit wide EPROMs and programming the (very little) code into them, so that I have a 32 bit wide bus and I don't need to modify the code. This is because I would like to try making a 68060 adapter for a 68040 board and I don't know if it will work at all, so it's better to start easy and then, if it works, make a better design :-)