Quartus Quirks 

Brought to you By DPF, 

Ben Talbot, David Ng, Mel Lumague, Nitin Parimi, Emy Egbogah

While using Quartus over the last 4 months., the DPF group have found a bunch of little tricks that not knowing about will bring your progress to a grinding halt

1. Programming switch

This was was the most annoying trick of all. Without the programming switches set properly you will not be able to program the board at all. Hence, it becomes a very expensive paper weight.

To have the Nios board accept new .sof files:

    a.  Place SW8 in the connect position.

    b. Place SW9 and SW 10 in the bypass position

Note: These switch are located right next to the seven segment display on the board.

2. Clear Pin

In the Nios development Guide Manual, it says that either N7 or F12 can be used as the clear button in the system. When we were testing the board we had problems getting the global clear to be issued properly when the reset was assigned to the F12 pin. This problem was fixed by using the N7 button instead.

3. Expansion Port Enable

When trying to get a demo up and running for the Resource Requirement, we could not get any signals, including the clock, out of the expansion ports. After 2 hours of surfing the Altera site we finally found the proper way to enable the expansion ports. All you have to do is assign pin V7 with a logical ground signal.

4. PLL Timers

Anything that uses the Video or SDRAM memory on the Nios board will probably have to use the PLL to get multiples/divisors of the clock. When looking at the Nios development board documentation, it says that if the clock is assigned to pin P5 with the altclklock module, multiples/divisors of the clock will be available on multiple pins of the board.

    Specifically,     JP10 pin 11

                            JP13 pin 11

                            PMC JN1 pin 13

                            J2 pin 61

                            J2 pin 74

But unfortunately it will not work. The problem with this approach is that other pins on the board are sinking current from the clock and no signal is created. 

To fix this problem just 

    - set all unused pins to tristated, so they will not sink any current

            complier settings ->  Chip & Devices -> Device and Pin Options -> Unsued Pins.

References:

Nios Embedded Processor Development Board Manual (Nios_Development_Board_Guide.pdf)