Apple has agreed to buy P.A. Semi, a boutique microprocessor design company, according to Forbes magazine. The deal is reportedly worth $278 million in cash.

Led by chip-industry veteran Dan Dobberpuhl, P.A. Semi is perhaps best known for its PWRficient processors for the multibillion-dollar high-performance embedded-computing markets. PWRficient 64-bit multicore processors aim to redefine power, cost and throughput efficiency in high-performance processing.

P.A. Semi’s processors could provide advanced features in future iPods and iPhones.

Deja Vu for P.A. Semi

The acquisition may be a dream come true for P.A. Semi, as well as deja vu. When Apple was ready to dissolve its relationship with IBM and its PowerPC processors, P.A. Semi was the rumored heir apparent processor maker for the Mac. P.A. Semi is an active member in Power.org and leverages IBM’s Power Architecture in its processors.

However, Apple selected Intel as its chipmaking partner for the Mac. This time around, it appears Apple CEO Steve Jobs is more concerned about a competitive advantage for the iPhone.

“P.A. Semi makes some great technology, very power-efficient and ideal for a variety of mobile devices. It does appear to be something of a slap in Intel’s face. Intel is making such a big deal of its Atom processor, which is aimed at that same market,” said Charles King, principal analyst at Pund-IT Research.

Intel’s Atom in the Wings

Indeed, Intel announced five new Atom processors and Centrino Atom processor technology for mobile Internet devices and embedded computing solutions earlier this month.

The technology package includes the Intel Atom processor (formerly code-named Silverthorne) plus a single chip with integrated graphics called the Intel System Controller Hub that enables PC-like capabilities, including an Internet experience and long battery life, in devices that can fit in your pocket.

“Acquiring P.A. Semi is an interesting opportunity for Apple that probably reflects the company’s tradition of…