I'm looking at the MCF5223x series and didn't notice a pa...

[Cuetek]

I'm looking at the MCF5223x series and didn't notice a parallel I/O port module?  Seems unlikely to me.  What am I missing?  -Mike

[Nouchi]

Hello Mike,

You should have a look to the Reference Manual chapter 14, you will find an answer.


Emmanuel.

[Cuetek]

Thanks Emanuel,

I guess what I was really hoping was that there was a  one cycle write strobe feature where I could send data out to an addressed set of latches with one instruction and a write strobe would be generated with the rising (or falling) edge occuring about 1/2 an instruction cycle after the data assertion.  As I see it from the GPIO section (14), I will be required to output the data and address with one instruction and then output the strobe with another, and I really need the speed.  Is this correct or am I still missing something?  Does the EPORT help me out with a synchonous write strobe?  I'm new to the Coldfire architecture. 

Thanks  -Mike

[mjbcswitzerland]

Hi Mike

The GPIOs and Edge ports in the M5223X series are general purpose ports and IRQs respectively. What you need is an external bus interface.

Look at some other parts (eg. the 5227x) which have a module called the FlexBus. This allows interfacing to memory etc.and you can see whether it has timing suitable for your requirements.

Note that the GPIO commands PORTIN_SET and CLEAR allow fast setting and clearing of specified bits and so some bit banging is not usually a big deal. To automate bit banging a memory interface there are also possibilities using the DMA timer support since it allows a sequence to be written to a port using timer controlled DMA accesses - although restricted to controlling 8 bits, which is probably not enough for most data buses.

Regards

Mark

www.uTasker.com



Message Edited by mjbcswitzerland on 2009-01-09 05:31 PM