Questions about going over to XMega

KokkeKat · Joined: 08 May 2011 Posts: 59 Location: Stockholm

Hi,

I am considering going from "5V Mega with FT232 USB" to XMega128A1U and wonder if somebody could help me with some general advice. Is it a big thing to reuse/convert general BASCOM code from Mega in an XMega design?

Any particular pitfalls that I should avoid?

Is it possible to use the definition file for 128A1 and do the USB stuff yourself directly on the registers?

Do I get this right? To use full-speed USB, you must set the internal 32MHz clock to 48MHz using the factory calibration data plus do custom calibration using for example an external 32.768kHz RTC clock. At 48MHz, the actual system clock must be divided by 4 to 12MHz?

I am very grateful for your input. Thanks in advance.

Kind regards

Niclas

JC · Joined: 15 Dec 2007 Posts: 586 Location: Cleveland, OH

The Xmegas have many great new features, and it takes a long time to learn them.

The initial learning includes learning the new syntax for setting up I/O pins for input and output, and readng and writing to them.

Also, as the Xmegas all boot up at 2 MHz, one generally sets the clock to the desired source and speed as part of their chip initializations. The Xmegas have many clock sources available.

Note that you will need a PDI programmer. The STk500 and some of the other ISP programmers available won't work with an Xmega. There are many Threads on AVR Freaks about whether or not the Atmel Dragon can successfully program Xmegas or not. The Atmel AVR ISP mkII, at about $34 USD, is relatively inexpensive and works well for programming just about all of the AVR chips, including the Xmegas.

Note also that the Xmegas do not come in plastic dip packages. If you are use to bread boarding your designs then you need to learn a new approach. One can use an Xmega breakout board plugged into a bread board, or use an Xmega development board, (or make your own). This Thread, at AVR Freaks, has links to many Xmega development boards:
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=119495&highlight=development

I can't comment on using the new USB module within the Xmega. I'm hoping that Bascom will provide a CDC (serial port), and HID USB set of instructions and an example soon!

JC

KokkeKat · Joined: 08 May 2011 Posts: 59 Location: Stockholm

Thanks JC!

Kind regards

Niclas

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

the setting up of ports is exact the same : config pin/port = input/output
you only have additional options with config xpin.

in the help you can read about the xmega.
i can recommend avrisp MKII too.

Kimmeridgien · Joined: 22 Feb 2007 Posts: 89 Location: Stockholm

Thanks Mark,

Just a quick question: The JTAGICE3 should also work with XMega? (I also have an AVRISP MkII, so no problem there.)

Kind regards

Niclas

MAK3 · Joined: 24 Sep 2010 Posts: 449 Location: Germany

Hi,

there is a lot of ATXMEGA documentation added in the last Bascom updates:

http://avrhelp.mcselec.com/atxmega.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/loader.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/config_adcx.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/config_portx.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/configxram.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/config_dmachx.htm?zoom_highlightsub=xmega

http://avrhelp.mcselec.com/config_xpin.htm?zoom_highlightsub=xmega

...
...

MAK3

enniom · Joined: 20 Oct 2009 Posts: 537

Niclas,

your question about programming Xmega with JTAGICE3 - should work - because it includes PDI programming capability.

From Atmel

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

the new jtagice is not supported by bascom. i do not have one to test to see what the problem is about. but it is of course supported by studio.

Kimmeridgien · Joined: 22 Feb 2007 Posts: 89 Location: Stockholm

Thanks!

mlcarter · Joined: 12 May 2009 Posts: 11

I'm just looking at using an ATxmega for the faster 12 bit A-Ds. I see it has to be programmed using the PDI interface
The question I have Re programming with an AVRISP MKII.
Is this achieved by hooking it onto the PDI pins somehow.?
Is it then possible to set fuses etc from Bascom?

JC · Joined: 15 Dec 2007 Posts: 586 Location: Cleveland, OH

The "Standard" PDI Headr Pinout is shown in the Atmel Application Note AVR042: AVR Hardware Design Considerations .

Section 4.3 shows a top down view of the 6-Pin Header routinely used for the PDI interface.

I use the AVR ISPmkII through AVR Studio V4 or V6.

Perhaps others can comment on using it from within Bascom.

JC

MAK3 · Joined: 24 Sep 2010 Posts: 449 Location: Germany

Hello,

mlcarter · Joined: 12 May 2009 Posts: 11

Thanks very much Your help. I'll have a go.
Just didn't seem right to program a single input/output data line with an SPI programmer with separate input and output!