CF pinout

[LGR]

The dsPIC CF library, according to the documentation, Uses two different 8-bit ports. If you look at the different dsPIC models, many don't have two seperate 8-bit ports available, as it is organized into 16-bit ports. There aren't many complete 16-bit ports either, but the library would be more flexible if there were an option of assigning all data and control pins to a single 16-bit port.

If the existing CF library will be abandonded in favor of the serial version that has been mentioned, this won't matter, but please give some advance information on what pins and modules will be used, so that different CPU models can be considered for different applications.

[zristic]

The dsPIC CF library, according to the documentation, Uses two different 8-bit ports. If you look at the different dsPIC models, many don't have two seperate 8-bit ports available, as it is organized into 16-bit ports.

'Many' is not the same as 'all'. As you know, we have to cover 'all' chips available and this is the reason why it is split into two 8-bit ports. Otherwise, GLCD lib would be different for each chip and it will make problems with transferring your code to other dsPICs.
Serial gLCD is still under construction, cannot comment yet.

[LGR]

You mean "CF"?

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There is a serious problem with the dsPICs when using any kind of parallel interface. Then you look at the entire line, from 18-pin to 80 pin, and count the number of ports with complete 8-bit or 16-bit registers, the list is very limited:

Code: Select all

Pins         8-bit ports    16-bit ports
18            0                     0
28            1                     0
40/44         1                     0
64            2                     1
80            3                     2

The only dsPICs that will work with the library either way, are the 64 and 80 pin! I think that the solution has to be to use some of the partial ports (for example, on the 40 pin, port F has 7 bits (F0-F6). This could be used in conjuntion with A11, perhaps? The 28 pin dsPICs could be used if portF (F2-F6) could be combined with port C (C13-15). Otherwise, the library will be limited to the extremely large CPUs.

[zristic]

You mean "CF"?

Yes, sorry.

I get your point. We are actually driven by hardware department and the way they connect modules to EasyPic boards. As for the extra boards, you are right that they should not be split to two ports. I will point this out at our next staff meeting (tomorrow morning).

[Guest]

As for the extra boards, you are right that they should not be split to two ports.

Actually, after analyzing the product family, my original idea doesn't make as much sense as I thought. It might add some flexibility to applications using the 64 and 80 pin dsPICs, but it won't help with the others. If the CF can be used with the 28 and 40/44 pin dsPICs, you will have to either use a combination of ports that are less than 8 bits (as described above), or go to the serial interface.

Since the dsPICs all have at least one, and most have two SPI ports, it might be smarter to emphasize the serial hardware option. I would just like to know more about the limitations of this approach. I would like to know if this would seriously impede throughput. I suspect not; SPI can operate at very high speeds, but I would like to know more about the exact details of the hardware that you are working on, and if you have any estimates of speed or any other limitations that may be introduced.

It doesn't seem that microchip had parallel interfacing in mind when they designed the dsPIC, maybe some form of serial GLCD interface may be a solution to consider.

[LGR]

That was me; I wasn't logged in.

[Storic]

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and if you dont make the same mistake twice
you have learnt something

[LGR]

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and if you dont make the same mistake twice
you have learnt something

Now you're asking for too much.