I am confused by the documentation. It states in the "Getting Started" book that the XTAL [directive in the Target dialog] specifies the CPU clock for my device. "In most cases this value is inentical with the XTAL frequency." When is it not? And if not what do I enter into the field? I am using the EZUSB part from Cypress. I believe that the actual CPU clock speed for a 12MHz crystal would be 48MHz. Should I enter 12 or 48?
I read that article in the first place and it did not answer my question either. It states that the CPU clock speed will be the result of dividing the Xtal frequency by an integer. The Cypress part has a PLL that brings the clock up to 24 or 48 MHz depending on boot configuration. Does the Keil compiler know this and adjust the clock speed up? How does it know what the boot configuration is? And, probably most importantly, what does this setting affect? The target device is set correctly to: Anchor Chips EZUSB 8051.
And, probably most importantly, what does this setting affect? Just a guess -- the elapsed processor execution time ("Regs" tab, in the "Sys" expansion) when simulating?