Even as GPPs steal sockets from DSPs in general-purpose markets, DSP are squeezing out GPPs in specialized apps.
Today's announcement of the TI OMAP35x is a sign of the times. While TI has traditionally used an ARM+DSP combination in its OMAP platform, two of the four devices in the new OMAP35x family skip the DSP and rely on a hand-optimized ARM Cortex-A8 ARM core instead.
Considering the heavy DSP load in the apps targeted by the OMAP35x (mobile internet devices, personal navigation systems, portable medical equipment, etc.), one has to wonder: is the DSP-enabled general-purpose processor (GPP) finally swallowing the DSP?
For general-purpose markets, the need for portability suggests that the answer is yes. Code written for a TI DSP will only run on TI chips. Code written for an ARM will run on chips from Freescale, Qualcomm, etc. This portability is critical for the general-purpose market: In order for 3rd-party software developers to justify the costs of writing new software, they need to be assured that there will be a sufficiently large market. Thus, it is far more attractive to write code for an architecture shared by multiple vendors than for a proprietary DSP.
For more specialized markets, however, it is unlikely that GPPs will take over. While the DSP performance of the Cortex-A8 and other DSP-enabled GPPs is impressive, DSPs benefit from architectural specialization that gives them a critical performance edge.
Indeed, DSPs are now displacing GPPS is many markets thanks to the hot new technology of virtualization. Virtualization software from vendors such as VirtualLogix and Softier enable DSPs to run multiple operating systems—Linux and a TI's DSP/BIOS for example. This makes it much easier for systems that once required a GPP+DSP architecture to run everything on DSPs.
For more on virtualization, check outVirtualizing Embedded Linux