From: "Anthony Q. Bachler"
Subject: Re: 65816 CPU @ 20MHz and 70ns EEPROM?
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Date: Tue, 21 Jan 2003 04:41:24 -0600
NNTP-Posting-Date: Tue, 21 Jan 2003 05:42:06 EST
The CAS/RAS timing is the manufacturers guaranteed maximum time from the
instant the address is selected until the outputs on the data lines are
guaranteed to be valid. The average chip is faster than this. this is just
the maximum allowed before the chip, or rather the entire lot, is chucked
into the next higher speed category.
"If a million people say a foolish thing, it is still a foolish thing."
Anatole France [Jacques Anatole Thibault] (1844-1924)
"Krystian Sergiejew" wrote in message
> > There are 2 solutions that I can see, depending on how much of an issue
> > price is, I'm assuming it is an issue since you don't want to just buy
> > faster EPROM's but Ill include the other solution just for arguments
> Actually, the cost isn't a problem here as this isn't a machine
> with a goal to make profit. In case of the EEPROM I might just use a
> version, although the fastest one I have seen was 55ns (2864), which
> another question: if an EEPROM is rated at 55ns, does that mean that in
> order to read its contents, the R of R/WB would have to stay high for
> In my case, if the bus is clocked at 20MHz, the clock cycle is 50ns, which
> means that the R/WB is 25ns high and 25ns low during one clock cycle,
> If so, in order to read the EEPROM I only have 25ns, right?
> Please let me know if I understand this correctly.