Linux Journal has an article on how the “the combination of a DSP and uClinux works especially well for the embedded Linux gadgets turning up everywhere in the consumer electronics market.”
Why would anyone use Linux on a DSP?
In the past, DSP’s have been used in a lot of applications including sound cards, modems, telecommunication devices, medical devices and all sorts of military and other appliances that perform pure signal processing. Those DSP systems generally were designed specifically for those applications and had only basic capabilities so as to meet their tight cost and size constraints. As DSPs have become more powerful and flexible, thereby servicing the more advanced requirements of military, medical and communication users, they still have lacked the proper capabilities to run advanced operating systems. Traditional DSPs are powerful and flexible but can be rather expensive. They often are found clustered together on special signal-processing hardware where there is no need to have an operating system such as Linux running on the DSP itself. This generally is due to the fact that in those systems the DSP gets its data from some type of additional central processing unit. Therefore, only basic system software had to be written for such DSPs.
Accompanied by the quickly advancing multimedia convergence and proliferation of multimedia and communication enabled gadgets, there now is a big market for a new type of DSP. Currently, the most widely used design for servicing these markets is the combination of a general-purpose processor with a traditional DSP serving as a co-processor. In this scenario, the operating system runs on the host processor and the signal processing is done on the DSP. This type of dual-processor design is sub-optimal, though, due to inefficiencies incurred in cost, power and size.
The combo could also work for multimedia-enabled thin clients.
On a related note, Slashdot writes that “Atmel is sampling the first in a new line of 32-bit system-on-chip processors that could spell the death of the venerable 8-bit microcontroller market by offering 32-bit performance at 8-bit pricing. Priced as low as $3 each, the AT91SAM7 chips with ARM7TDMI RISC CPU cores and built-in RAM/flash memory may even be able to run a form of Linux called uClinux.”