Lpc2000

On Fri, Jun 04, 2004 at 12:36:08PM +0200, Larsen, Morten ActeNO wrote:
>    
>    PS,PS: just curious - could you give a "Real-Worl" example
>    of an appliction for an 8-pin ARM7, where a 8-bit MCU wouldn't do??

The world goes serial. Well of course a 64pin device is more multipurpose
(and sells in larger quantities), so probably no vendor will see a reason to
provide smaller packages just for some applications. But there are many
applications, e.g. motor-subcontrollers (controller integrated in the motor
and communicate as I2C-Slave device), of course this could be solved with a
8bit micro in most cases. A AD converter with integrated signal processing
is more cpu intensive. Today there are sensors with integrated EEPROM for
parameter storage available. But the signal is still analog. Replace te 8
pin EEPROM by a 8 pin controller with AD and serial interface you have
powerful sensors with integrated signal preprocessing. That devices need
probably much RAM for the data aquisition. (well of course you can do this
at low speed with a 8bit micro too, but high speed applications are
also possible).

 When the devices are cheap enough you can also replace complicated hardware
just by software. In this case speed matters. With a 8bit CPU you can
probably just work up to 100kHz with a 100MHz ARM you get 10-50 times faster.
(or use a FPGA).

In short: in most cases I would use them as subcontrollers - for timecritical
tasks that let no time left in the main controller and/or for machanical
simplification. A important point is, that these 8pin micros should
have a very fast serial interface (at least I2C-slave and SPI, but SPI
need much pins) to get the data with high speed out.

Today a ARM7 sound overkill, but tomorrow we will see ARM's everywhere.
Btw. I also miss small ("serial") FPGA's.

M.