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µVision User's Guide

About µVision User Interface Creating Applications Debugging Start Debugging Start Energy Measurement without Debug Application Program Execution Debug Windows and Dialogs Breakpoints Window Call Stack and Locals Window Code Coverage Command Window Component Viewer Disassembly Window Editor Window Event Recorder Setup Event Recorder Event Recorder Window Events Filtering Event Statistics Window Post-mortem Analysis Event Viewer Execution Profiler Instruction Trace Window System Analyzer Usage tips Save System Analyzer Contents Statistics Restrictions Logic Analyzer Setup Setup in Detail Restrictions Cortex-M Trace Configuration Memory Map Memory Window Performance Analyzer Registers Window Serial Window Debug (printf) Viewer Symbols Window System Viewer Adding System Viewer Windows System and Thread Viewer Thread States Toolbox Trace Data Window Trace Navigation Trace Exceptions Event Counters ULINKplus Window Watch Window Core Peripherals Cortex-M0 and Cortex-M0+ Nested Vector Interrupt Controller System Control and Configuration System Tick Timer Fault Reports (Cortex-M0+ only) Cortex-M3, Cortex-M4, and Cortex-M7 Nested Vector Interrupt Controller System Control and Configuration System Tick Timer Fault Reports Memory Protection Unit Cortex-M23/M33/M35P and Cortex-M55 Nested Vector Interrupt Controller System Control and Configuration System Tick Timer Fault Reports Memory Protection Unit Security Attribution Unit M-Profile Vector Extension (MVE) Debug Scripting Expressions Constants System Variables Peripheral Variables I/O Ports Serial Ports Program Variables (Symbols) Fully Qualified Symbols Non-Qualified Symbols Literal Symbols Using Symbols Line Numbers Bit Addresses Type Specifications Memory Attribution Specifiers Operators Differences between µVision and C Expression Examples Code and Data Trace (Cortex-M) Trace Features Configuring Trace Tracepoint Expressions Tracepoint Intrinsics Tracepoint Limitations Tracepoint Marks Tips and Tricks Review Peripherals and CPU Configuration Simulate I/O Ports Simulate Interrupts and Clock Inputs Simulate external I/O Devices Assign Serial I/O to a PC COM Port Check Illegal Memory Access Command Input from File Preset I/O Ports or Memory Contents Write Debug Output to a File Keyboard Shortcuts TPIU Initialization after RESET (Cortex-M) Prevent Opening Files Show Japanese Messages Debug Commands Debug Functions Simulation Flash Programming Dialogs Utilities Command Line Example Programs Appendix

Peripheral Variables

A number of symbols get defined automatically depending on the CPU you have selected for your project:

  • Peripheral Registers (or special function registers, SFRs), and
  • Virtual Simulation Registers (VTREGs).

Debug Functions can be used to automate input to peripherals. Refer to Simulation Script Templates.

See also:

Peripheral Registers

µVision defines symbols for peripheral registers. The available peripheral register symbols depend on the selected microcontroller. They have an associated address and can be used in expressions.

Virtual Simulation Registers (VTREGs)

Virtual Simulation Registers, or VTREGs, let you use the CPU's simulated pins for input and output. VTREGs provide a way to specify signals coming into the CPU from a simulated piece of hardware. VTREGs are not public symbols nor do they reside in a memory space of the CPU. They can be used in expressions, but their value and utilization are CPU dependent. You can list these symbols with the command DIR VTREG.

The following table describes VTREG symbols.

VTREG Description
ADx Analog input pins on the chip. Typically, A/D converter inputs. Your target program may read values you write to ADx VTREGs.
DAx Analog output pin on the chip. This values typically reflect the output of a D/A converter.
xxVREF Input for voltage reference pins.
PORTx Group of I/O pins for a port on the chip. For example, PORTA refers to all pins of PORTA. These registers allow you to simulate port I/O.
SxIN Input buffer of serial interface x. You may write 8-bit or 9-bit values to SxIN. The values are read by your target program. You may read SxIN to determine when the input buffer is ready for another character. The value 0xFFFF signals that the previous value has been processed completely and a new value can be written.
SxOUT Output buffer of serial interface x. µVision copies 8-bit or 9-bit values (as programmed) to the SxOUT VTREG.
SxTIME Defines the baudrate timing of the serial interface x. When SxTIME is 1, µVision simulates the timing of the serial interface using the programmed baudrate. When SxTIME is 0 (the default value), the programmed baudrate timing is ignored and serial transmission time is instantaneous.
CLOCK Real clock frequency of the simulated CPU.
XTAL Crystal frequency of the simulated CPU as defined in Options for Target dialog.
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