X-Mega AVRs are here!

Only thing missing is a LCD segment driver. Otherwise, we would jump right into it.

And an extra 24 bits of register width... And a Von Neumann architecture. :)

It's fair enough that it's an 8-bit architecture, but they could have put a little effort into fixing the most glaring design flaws of the cpu. Why not drop the fmul* instructions that almost never get used, along with the rcall opcodes (I guess they are used by Forth systems, but I can't see they are much use to a C compiler), and add some of the features that would have made a real difference to the cpu power for C programming? Adding an X+q mode comparable to the Y+q and Z+q, and making R24:R25 a forth pointer register would be a big help. Support for (SP+q) addressing would be a benefit, although it would not be too important if it there was more if a forth pointer with W+q addressing modes existed. A method of atomically accessing the 16-bit stack pointer would be useful, however.

As for making it entirely von Neumann, I think that's a bit too big a change - but it would have been perfectly possible to make the flash accessible in the data space as well (in the same way as the eeprom is now mapped into the data space). You'd need 24-bit pointers to access it, but it would still be a very useful feature.

It's also missing a CAN controller, and the SDRAM setup is a bit odd (it should be possible to get an 8-bit SDRAM bus using only three ports).

Apart from that, it looks a very nice chip, which we will probably find use for. Maybe I can use it to drive my QVGA screen...

Adding to the AVR wish list. Having access to the SPI engine from the CPU would be nice. There are many features of the uC available to external SPI access, but impossible to do internally. For examples: fuses and lock bits, flash and eeprom.

Missing in these devices is any mention of LIN support ?

(but they do have a truckload of serial ports, and Quadrature counting, Ulf left of his list..)

Peripherals is where all the action is these days.

-jg

You mean the programming interface ? flash and eeprom are surely available ?

Fuses ? - a good uC should be able to READ the fuse status, but IAP programming them is a different call: Higher risk, and lower security ?

-jg

No more riskier than being able to reprogram the flash. They can have a very complicated sequence to change the fuses/locks.

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nt

Atmel introduced the SAM7L series a few days ago, which is low power and has an LCD segment driver, but meager SRAM (always something!)

But it does not come in 44 pins. We are small people working on small projects, so smaller chip is better. We need 16K flash, 4 A2D and

A 44 pin device with LCD drive would be a very unusual animal ?.

You might be better off with 2 chips, a 'uC of your choice', and a LCD driver chip ?.

On the subject of the AT91SAM7L - anyone seen a price on the Eval Kit - that has a nice looking LCD ?

-jg

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I think only microchip makes small 28 and 44 pin LCD devices that are close to what you need

Yes, I think the 16F913 w/ 28 pin QFN is what I need. Unfortunately, I have to learn pic now.

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you have my sympathies

is your "small" constraint more size or price? you can use any old micro to drive an segmented LCD, but requires external parts (cheaper but bigger)

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Both. I guess more for price than size.

Yes, it is in the drawing board as well. We need an external charge pump and regulator to constant 3V from 2V to 6V battery range. Luminary Micro ARM Cortex M3 is also possible.

Which of course require a new compiler... The decision was made to not change the CPU core.

The AVR core supports 16 MB dataspace and 8 MB instruction space. I think that if the code was mapped to the upper 8 MB of the dataspace there would be no conflicts. Again, such a change would probably affect the compilers, which was undesirable.

I assume that the fancy stuff will come in future chips.

I think that you might be able to create a simple LCD controller with the X-Mega DMA controllers, timers and the event handling.

Yes, as long as we can set the outputs at 3V, regardless of battery voltage.

You have a PLL with 4 x CPU clock (128 MHz) connected to a timer, so It may be possible (didn't check) that you can do a switch regulator for some of the I/O pins.

meddelandetnews: snipped-for-privacy@x30g2000hsd.googlegroups.com...

Yes, the external oscillator, booster and regulator will be assisted by uC software. It will be a combinations of transistors, diodes, resistors, capacitors and mutual inductors. Actually, we already have the circuit in the production device, but they are not yet populated and activated. We just want to make sure there is enough space for it. The power circuit is on a separate circuit board, so no space limitations there. However, the uC must fit inside the 0.8" width of the LCD glass. It is very tight with the 64 pins MLF.