The PB0 pin on the RCM3700 core module is used internally for Serial Flash, but it’s also available on the 20x2 pin header of the RCM3700.
Since we believed all external pins were available, we used this pin for controlling our display… since this pin is also used for serial flash controler, we can use either, but not both at the same time…
There are other, not used, ports available on the rabbit 3000 processor… So there must be a good reason for bringing PB0 external…
So my question is, why was it done? (So i might learn something of our costly mistake)…
[QUOTE=IWriteCode;112]The PB0 pin on the RCM3700 core module is used internally for Serial Flash, but it’s also available on the 20x2 pin header of the RCM3700.
Since we believed all external pins were available, we used this pin for controlling our display… since this pin is also used for serial flash controler, we can use either, but not both at the same time…
There are other, not used, ports available on the rabbit 3000 processor… So there must be a good reason for bringing PB0 external…
So my question is, why was it done? (So i might learn something of our costly mistake)…[/quote]
It is done to allow more flexibility for designers. If you are not using the serial flash, or are willing to take some care on when you talk to it, the port can be used for other purposes. It is not at all uncommon to share SPI ports between multiple devices and since the serial flash uses a chip select on port PE6, you can easily do that as long as you account for it in your coding.