I've gotten a lovely sine wave tonight out of my XMEGA A sample on its PA2 pin using its integrated DAC. What fun it is to have an AVR output analog signals. I'm using an assembly language output loop of 9 cycles running at 32MHz using a 24-bit phase accumulator and 8-bit output. Next step will be to use 12-bit output.
- The 2 MHz internal oscillator is well-calibrated. Using the PLL to boost to 32 MHz is just plain fun. A sine wave that should be 1000.086 Hz measures 1000.09 Hz on my Fluke ScopeMeter.
- Goodbye "magic" frequency crystals for UART output. With the 4095 possible values of BSEL (the replacement for UBRR) and using BSCALE to bit shift BSEL from -7 to +7 bits, it's possible to get very close baud rates, even with formerly impossble situations like 115.2Kbps with a CLK of 1MHz and 300 baud with a CLK of 32MHz. I'm extending AVRCalc ( http://www.avrcalc.com/ ) to handle selecting the best BSEL and BSCALE for a given clock frequency and desired baud rate.
- Mouting on a STK600 and using a JTAGICEMkII for programming/debugging works as well as one would expect. Performing this on a MacBook Pro using VMWare Fusion and WinXP works better than I would have expected. I'm looking forward to when AVR ONE supports XMEGA debugging using PDI.
I wonder if I just posted the first XMEGA usage report?