Unformatted text preview: re easier to port to a new process technology than is the hard macrocell. The synthesis process supports a number of optional variations on the processor core functionality. These include: omitting the EmbeddedlCE cell; replacing the full 64-bit result multiplier with a smaller and simpler multiplier that supports only the ARM multiply instructions that produce a 32-bit result. Either of these options will result in a smaller synthesized macrocell with reduced functionality. The full version is 50% larger and 50% less power-efficient than the hard macrocell. ARM7TDMI applications The ARM7TDMI processor core has found many applications in systems with simple memory configurations, usually including a few kilobytes of simple on-chip RAM. A typical example is a mobile telephone handset (where the same chip usually incorporates sophisticated digital signal processing hardware and associated 256 ARM Processor Cores memories), where the ARM7TDMI has become the de-facto standard processor for the control and user interface functions. Where significantly higher performance is required than can be delivered by a straightforward ARM7TDMI with a simple memory system, the system complexity will inevitably increase. The first step is to add a cache memory to the ARM7TDMI, probably in the form of an ARM CPU macrocell. This will enhance the performance of the software running from off-chip memory. If this still does not yield sufficient performance for the application, a more complex ARM core must be used that is capable of operating at yet higher performance levels. The ARM9TDMI and ARM10TDMI are such cores and are described later in this chapter. 9.2 ARMS
The ARMS core was developed at ARM Limited from 1993 to 1996 to supply the demand for an ARM core with a higher performance than was achievable with the ARM? 3-stage pipeline. It has now been superseded by the ARM9TDMI and ARM10TDMI, but its design raises some points of interest. As was discussed in Section 4.2 on page 78, the performance of a processor co...
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This document was uploaded on 10/30/2011 for the course CSE 378 380 at SUNY Buffalo.
- Spring '09