SA-1110/Applications Processor Migration

Intel® XScale™ microarchitecture

Debugging

-Cache attributes

-Other Features

-Conclusion

A.1 SA-1110 Hardware Migration Issues

A.1.1 Hardware Compatibility

The majority of the features provided in the SA-1110 are also provided in the PXA250 applications processor. However, with the additional functionality of the PXA250 applications processor, the two devices are not pin compatible and cannot occupy the same socket.

There has been an effort to ensure Companion Devices that take advantage of SA-1110 memory interface access works with the PXA250 applications processor. The memory controls for taking over the memory bus such as those exercised by the SA-1111, are included in the PXA250 applications processor memory bus interface however, there are some issues.

One difference in particular is the way PXA250 applications processor toggles the A1 and A0 address lines. The SA-1110 toggled A1 and A0 regardless of the size of the data bus. With PXA250, if the data bus is set to 16-bit, then A0 does not toggle and if the data bus is set to 32-bit, then neither A1 nor A0 toggles.

There is a big difference in manufacturing technology between the SA-1110 and the PXA250 applications processors. The most significant change being from a 0.35 micron CMOS technology to a finer lithography of 0.18 microns. Aside from a potential impact to signal edge rates this allows for lower applications processor voltage operation.

A.1.2 Signal Changes

There are two pins that control SA-1110 boot-up:

ROM select pin that selects a 16 or 32-bit interface

Synchronous Mask ROM enable pin that selects a synchronous or asynchronous ROM access

The PXA250 applications processor has three pins that select eight different boot select options (see Table A-1. The subset of these options that are SA-1110 equivalent are not compatible with the PXA250 applications processor pin polarities, so these pins must be selected afresh when designing with the PXA250 applications processor.

Table A-1. PXA250 Boot Select Options (Sheet 1 of 2)

 

Boot Select Pins

 

 

 

 

 

 

 

Boot Location

2

 

1

 

0

 

 

 

 

 

 

 

0

 

0

 

0

Asynchronous 32-bit ROM

 

 

 

 

 

 

0

 

0

 

1

Asynchronous 16-bit ROM

 

 

 

 

 

 

0

 

1

 

0

Synchronous 32-bit Flash

 

 

 

 

 

 

A-2

PXA250 and PXA210 Applications Processors Design Guide

Page 96
Image 96
Intel PXA250 and PXA210 manual SA-1110 Hardware Migration Issues, Hardware Compatibility, Signal Changes

PXA250 and PXA210 specifications

The Intel PXA250 and PXA210 processors, part of the Intel XScale architecture, were introduced in the early 2000s, targeting mobile and embedded applications. They are known for their low power consumption, high performance, and advanced multimedia capabilities, making them suitable for a wide range of devices, including PDAs, smartphones, and other portable computing devices.

The PXA250, which operates at clock speeds ranging from 400 MHz to 624 MHz, features a superscalar architecture that allows it to issue multiple instructions per clock cycle. This enhances the overall performance for demanding applications while maintaining low power usage. It supports a variety of peripheral interfaces, including USB, Ethernet, and various memory types, which contributes to its versatility in different product designs.

One of the key technologies in the PXA250 is the integrated Intel Smart Repeat Technology, which optimizes data processing, thereby reducing the amount of power consumed during operation. This feature is particularly important for battery-powered devices, as it extends the overall battery life, allowing for longer usage times in mobile environments. Additionally, the PXA250 includes a dedicated graphics acceleration unit, which enables enhanced graphics and multimedia performance suited to modern applications at the time.

In contrast, the PXA210 is a more entry-level processor, aimed at cost-sensitive applications. Operating at lower clock speeds, typically around 200 MHz to 400 MHz, it forgoes some of the advanced performance features of the PXA250 while still offering a good balance of performance and power efficiency. The PXA210 is less complex, making it suitable for simpler devices that do not require the extensive capabilities of the PXA250.

Both processors utilize the Intel XScale architecture, which is based on the ARM instruction set. They are built on a 0.13-micron process technology, enabling higher density and lower power consumption compared to their predecessors. With integrated memory controllers and bus interfaces, they facilitate efficient data handling and connectivity options.

In summary, both the Intel PXA250 and PXA210 processors played a crucial role in the evolution of mobile computing by providing powerful processing capabilities with energy efficiency. Their features and technologies enabled device manufacturers to create innovative products that catered to the growing demand for portable devices during that era.