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PORT LINES DON'T TOGGLE DURING MEMORY ACCE

Applies to: uVision Debugger

Answer


Information in this article applies to:


QUESTION

I have a program that writes to external memory. I can view the values written in the memory window. The external bus interface of my device also toggles the I/O port pins. Is it possible to see also the toggles on the I/O ports when I use the dialog Peripherals - I/O Port?

ANSWER

No, the uVision simulator is not a cycle-based simulator and, therefore, it is not possible to see the memory access on the I/O Port lines.

To provide fast simulation speeds, uVision simulates a single instruction in one step. The behavior of on-chip peripherals and memory accesses is completely simulated at the logic level but not at the gate level. Therefore, you cannot see I/O port toggles of the peripherals or memory access. Instead, the logic behavior of the peripherals is reflected in virtual registers that are listed with the DIR VTREG command. This has the benefit that you can easily write debug functions that simulate complex peripherals.

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Article last edited on: 2004-06-28 21:35:27

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