Aaron Kulkis wrote:
James Knott wrote:
Aaron Kulkis wrote:
A true modem doesn't have an on-board CPU. Not even 56k modems using frequency, amplitude, and phase shifting. There are hybrid digital/analog ICs (integrated circuits) which dothis right from the factory, needing only connectivity to power, a few external discreet elements (resistors, capacitors and/or
I think you'll find even those chips have an embedded CPU in 'em.
Those CPUs are only to implement the Hayes command set, and those don't need any external drivers, either, because the programming needed to run that is all self-contained in some sort of ROM (seperate, or on-chip if it's something like a Motorola 68HC11 microcontroller.
There's more than just the command set. Modems are also capable of data compression & error detection among other things, that while technically possible with custom logic are simply easier to implement in a CPU. BTW, what do you think is at the heart of a microcontroller? A microcontroller has a CPU, memory and I/O all built into one package. Take a look at this info on the 68HC11: http://bd.thrijswijk.nl/mcca1/68hc11_intro.htm A designer who needs a custom chip will take a microcontroller and program it to do what he wants, slap a new part number on it and ship it in a product. -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org