Solarwinds will do that, along with any number of competing products rangingn from the free (no acquisition cost anyhow) MRTG up to something like the heavy duty enterprise class Lucent VitalNet (>US$100k software cost).
Begging the question of why you need to monitor switch CPU. These are typically designed such that the CPU can handle switching all the ports with full line rate traffic moving through it and not be overloaded.
One might monitor port utilization for charge back purposes, to inform redesign activiites, monitor carrier performance, etc.
More important than what you monitor (and the tools you use to do so) is what do you do with the information. I've seen too many monitoring systems just feed hard drives and not decision-making. Take the time to integrate your monitoring into your deicision making in a structured way and it will pay more dividends than a wonderfullly elegant technical solution monitoring in a vacuum.
Hope this helps. Please rate it if it does.
