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Unformatted text preview: e CPI performances when running the dhrystone benchmark; other programs may give rather different CPI results, and the 64-bit data buses enable the ARMIOTDMI to deliver a significantly better effective CPI than the ARM9TDMI on complex tasks such as booting an operation system. 266 ARM Processor Cores ARM10TDMI applications It was noted in the discussion of 'ARM9TDMI applications' on page 262 that at least some local high-speed memory was required to release the performance potential of the core. The same is true of the ARM10TDMI: without separate local 64-bit instruction and data memories the core will not be able to deliver its full performance, and it will go no faster than a smaller and cheaper ARM core. Again, the usual (though not the only) way to resolve this problem is through the provision of local cache memories as exemplified by the ARM1020E described in Section 12.6 on page 341. Since the performance of the ARMIOTDMI core is critically dependent on the availability of fast 64-bit local memory, discussion of its performance characteristics will be presented later in the context of the ARM1020E. 9.5 Discussion
All early ARM processor cores, up to and including the ARM7TDMI, were based on a simple 3-stage fetch-decode-execute pipeline. From the first ARM1, developed at Acorn Computers in the early 1980s, through to the ARM7TDMI cores in most of today's mobile telephone handsets, the basic principles of operation have barely changed. The development work carried out in the ARM's first decade focused on the following aspects of the design: performance improvement through critical path optimization and process shrink age; low-power applications through static CMOS logic, power supply voltage reduc tion and code compression (the Thumb instruction set); support for system development through the addition of on-chip debug facilities, on-chip buses and software tools. The ARM7TDMI represents the pinnacle of this development process, and its commercial success demonstrates the...
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This document was uploaded on 10/30/2011 for the course CSE 378 380 at SUNY Buffalo.
- Spring '09