SoC Designer

One of my recent job is to pick a new microcontroller for our SystemOnChip, which has been using 8051-family for years. Since the ARM core is the new 8051 for SoC design, we contacted ARM for performance evaluation tool or kit. Their answer is SoC Designer, a complete software emulation of the whole SoC.

SoC is not the microcontroller/processor only. When we say System On Chip, it is really a system. We have various buses running different protocols at different clock rates. We have multiple processors, usually MCU+DSP. We have FLASH, EEPROM, DRAM and SRAM. We also have countless hardware components which work concurrently to off-load the main processors. And we are talking about a humble CD-ROM drive.

Precise and meaningful performance evaluation is really a tough job, so we just focused on the processor, cache, and FLASH subsystem.

The nice point for SoC Designer is you may model the system completely in software before the hardware is available. You may also simulate bugs or exceptions in software again and again without spending hours re-producing the situation with the real "embedded" hardware.

The problem for SoC Designer is you have to model all, or at least large part of your system before you can really evaluate the performance of it with real firmware. To make things worse, the ready-to-use model for processors, cache, bus, and memory components are not so reliable when it comes to cycle-accuracy. Without strong support, which we do not have, we cannot explain many performance differences and micro behavior of those models.

The idea is great, but we need more experience to trust this tool.