Intel PXA27X manual Introduction, Naming Conventions

Intel® PXA27x Processor Family Power Requirements

1.0Introduction

The Intel® PXA27x Processor Family (PXA27x processor) is a highly integrated system-on-chip optimized for handheld battery-powered devices such as PDAs and 2.5G or 3G cell phones. The PXA27x processor is ideal for products requiring substantial computing and multimedia capability with very low power consumption.

The PXA27x processor combines a high-performance CPU with a variety of integrated peripheral functions. The processor has separate power supply domains for the processor core, memory, and peripherals to enable low-power system design. The PXA27x processor provides several dedicated control signals as well as an I2C interface to connect to an external power management integrated circuit.

Other system components, such as SDRAM and flash memory, audio codecs, touchscreen controllers, and specialized companion chips, have with their own unique power requirements. In many designs, a highly integrated power controller supplies power for these other components, particularly those that interface directly to the PXA27x processor. An advanced power controller can contain circuitry for charging batteries, powering the display panel, and include other analog functions required by the system.

In any system design, factors such as operating conditions, application workload, environmental considerations and the sophistication of the device’s power management software all play a role in determining the amount of power consumed. When designing a system, manufacturers need to take into account where the device is intended to be used (such as high temperature environments) and what it is expected to do for an end user (such as play a game, a video or do simple email transactions).

The Intel® PXA27x Processor Family EMTS provides manufacturers with a typical system power consumption specification for all frequencies of the processor family. The purpose of this application note is to provide guidance on how power consumption, in a typical environment can change, based on different software workloads. In addition, this application note provides further details on the requirements for providing power to the processor and for interfacing to its power control signals, including behavioral requirements and typical system design examples under these workloads.

The power numbers generated utilized Intel development platforms in lab conditions and the information provided should be used as a guideline only.

1.1Naming Conventions

In this document, active low items are prefixed with a lowercase “n”. nRESET

Bits within a signal name are enclosed in angle brackets:

EXTERNAL_ADDRESS<31:0> nCS<1>

Bits within a register bit field are enclosed in square brackets:

REGISTER_BITFIELD[3:0]

REGISTER_BIT[0]

Application Note 5