6. There Is No "Intel Inside" CPU, But The Processor Is Economical, Thanks To DVS

As with the iPAQ H1940, HP uses a Samsung CPU. Samsung's S3C2440 is the successor model of the S3C2410 . Similar to Intel's Xscale processors , Samsung packs much more into the 196 mm² device than just the CPU core.

Block diagram of the S3C2440

The new application processor has three important new features versus its predecessor:

Higher core clock speeds of up to 533MHz; Integrated camera interface; Improved power management through Dynamic Voltage Scaling.

Counter to what the block diagram indicates, the iPAQ rx3715's S3C2440 processor only clocks in at a maximum speed of 400 MHz.

Unlike in the block diagram, the core of the S3C2440 in the iPAQ rx3715 operates with a maximum clock speed of 400 MHz. Maximum because Samsung's application processors feature - as a microprocessor for use with mobile devices should - an array of power-saving mechanisms. Software controls reductions in the CPU, system and periphery bus clock speeds as well as the deactivation of individual function blocks when little power is needed. In addition, the supply voltage can be reduced by over 20% for even greater energy savings.

The S3C2240 has four modes: Normal, Slow, Idle and Sleep.

In Normal mode, all function blocks of the processor are active including the core. Nonetheless, the clock signals of individual periphery blocks like the IR interface can still be selectively deactivated via software.