VemsFrontier/ARM

This page is about different ARM processors

The aim is to use an ARM7 chip.

We are biased towards the atmel AT91SAM7A3 (instead of the old plan, LPC2129).

The page ArmProcessorSubsitution contains a mapping of a GenBoard/VerThree port on a Philips LPC2119. The chip seems to me too tight. (Alexei)

The ancient page still has some info:

http://www.squirrelpf.com/msavr/index.php?page=BrainStorming


on-chip peripherals - was used as checklist when looking for uC candidates

The following points are important from my point of view:

the usage is obvious in most cases, check GenBoard/VerThree


Timer related

datasheet from page 214.... (and pinout)

YESS. This chip is awesome!

We have 8 input captures available: CAM / crank, crank-backup + 4 wheels + freqoutput MAP possible with 8 input captures!

PWM-ing uses it's own timer (at adress 0x14000) NOT Timer0/Timer1. The manual is confusing, but if you look at the registers and addresses (eg. page 230 of 306), it will be clear.

We'll use 40 .. 80 usec PWMing period .


Little guy needed or not?

Aren't we using an AVR (IO chip) to take care of Injector PWMing and flyback control? I feel that the IO chip is the best way to avoid pin mapping conflicts with the ARM boards. -J├Ârgen

No, it seems functionality per board was shrinked so much we don't need an AVR helper script. Pinmapping will be relatively easy, the only thing I asked is we

Even with arbitrary pinmapping it's _much_ less software than with a helper AVR chip, so we don't use that if not absolutely necessary.


packaging

price

availability, product maturity

I'm against new products like Motorola MAC71xx, the first version is always buggy


The MCU choice:

Philips LPC

- OKI [ML67Q2301] ? LQFP144, 4.5-5.5V, 384K, 16K, 4xCAN is DEAD, it never made to market

- Atmel: only BGA are with flash, rejected

- Motorola MAC71xx: not mature, rejected ?

- TI ?

- Cirrus Logic ? no ADC, BGA only, rejected

- ST: very similar to Philips LPC. 64pin package, 4 timers, 4x10bit ADC, USB or CAN, one 3v power. Inputs not 5v tolerant. BUT: eval kits developped 2 floors below my office :-)

- XC166 (someone put it on the bad page? oh, it's not ARM) could be acceptable but not enough reasons listed to switch from LPC2119

- design our own: (just kidding :-)


See also: