[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
This is a general comment about the 5V/3.3V question you have.
The 5V tolerance you mention does not affect the DRAM interface. It's OK to switch on and off the 5V and 3.3V at the same time. It's however not recommended to first switch the 5V on and then the 3.3V eventhough that probably works in the case of DRAM.
Sent: fredag, augusti 25, 2000 11:47
EDO DRAM is getting hard to find and Distributors keep trying to persuade
me that I should really be trying to design in SDRAM.
However 5V EDO DRAM is fairly readily available at sensible cost in the
form of 72 pin Simms.
Our main problem with this is that the ETRAX 100 chip is not
unconditionally 5V tolerant - if we have a mixed 5V/3.3V design we either
have to use buffers or we have to have phased starup/shutdown - both of
which are messy, add cost and have other implications.
Also - long term do Axis plan to produce ETRAX chips which interface with
Andrew J. Baker