Re: ARM7 with longevity of supply
- From: "Ulf Samuelsson" <ulf@xxxxxxxxxxxxx>
- Date: Wed, 15 Nov 2006 19:15:57 +0100
Tom Lucas wrote:
I have a design based around a Z8 Encore which is soon to grow beyond
the capabilities of the Z8. Several of our other products are based
around Intel 80188 microcontrollers and it was initially thought that
this would be a good route to upgrade seeing as we already have the
tools and knowledge.
However, I also have tools for ARM based processors and knowledge
there too so I thought it would be more sensible to go straight to
ARM and side-step the looming obsolescence issues with the 80188.
ARM7 should be more than enough for what I need.
I've narrowed down my choices using the following criteria:
* Must have full IAR compiler support including headers, flashloaders
and examples.
* Must have an external bus to connect to 8bit peripherals and also
RAM/ROM.
* Must have JTAG interface.
* Must have minimum 16bit timers, preferably 32 bit.
* Must have watchdog timer.
* Must not be in a BGA package.
I believe this narrows the selection down to the following parts:
Freescale MAC7111
Phillips LPC2292/2294
ST Electronics STR710/750 (non-BGA flavours)
Are there any that I've missed? Are these parts likely to have some
sensible longevity? 3 years would be good, five better. I've been
burnt before with manufacturers suddenly deciding to discontinue
products and don't want to get burned again. It would also be handy
if they came with a good reference design.
If you need external bus to connect to 8 bit peripherals,
there are plenty of AT91 chips around.
AT91M40800
AT91M42800A
AT91M55200A
AT91R40008
They are all microcontrollers requiring external flash.
The new AT91SAM7SE512 has SAM7S features and an external bus.
There will be pincompatible versions available soon with less than 512 kB
Flash
If you already decided you need external flash/RAM you should
also consider the AT91SAM9260.
Dirt cheap and runs 3-4 x performance of ARM7TDMI at 200 MHz.
It is available in a 208 PQFP package.
An SPI Dataflash (pin compatible from 1 Mbit to 64 Mbit) and a cheap SDRAM
and you are in business.
The BootROM allows for real easy production.
Connect the CPU SPI bus with a flat cable to the testsystem
The testsystem has a an SPI flash with the production code.
Alternatively, you can have an MMC connector and have the flash in a
flash card.
Reset the CPU.
When the CPU boots up, it will boot from the flash(card) in the testsystem
and copy
the image into another SPI flash residing on your production board.
Remove the cable and press reset.
The CPU will now boot from the internal SPI flash.
--
Best Regards,
Ulf Samuelsson
ulf@xxxxxxxxxxxxx
This message is intended to be my own personal view and it
may or may not be shared by my employer Atmel Nordic AB
.
- References:
- ARM7 with longevity of supply
- From: Tom Lucas
- ARM7 with longevity of supply
- Prev by Date: Re: ARM7 with longevity of supply
- Next by Date: Re: ARM code crash on symbian 8.1b device
- Previous by thread: Re: ARM7 with longevity of supply
- Next by thread: Re: ARM7 with longevity of supply
- Index(es):
Relevant Pages
|
