126 Chapter 5. Testing Programs
Structure Examples
>save_record[0] |
/* Address of a record */ |
0x002100A |
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>save_record[0].time.hour = DPP3 |
/* Change struct element of records */ |
>save_record[0].time.hour |
/* Interrogation */ |
0x03 |
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µVision2 Debug Function Invocation Examples
>printf ("uVision2 is coming!\n") |
/* String constant within printf() */ |
uVision2 is coming! |
/* Output */ |
>_WBYTE(0x20000, _RBYTE(0x20001)) |
/* Read & Write Memory Byte */ |
> |
/* example useful in debug functions */ |
>interval.min = getint ("enter integer: ");
Fully Qualified Symbol Examples
>--\measure\main\idx |
/* Auto INC/DEC valid for qualified symbol */ |
0xFFFF |
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Tips and Tricks |
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The following section discusses advanced techniques that you may use with the |
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µVision2 debugger. You will not need the following features very often, but |
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readers of this section get a better feeling for the µVision2 debugger capabilities. |
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Simulating I/O Ports |
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µVision2 provides dialogs that show the |
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status of all I/O ports. The I/O Pins are |
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represented with VTREGs. You may use this |
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VTREGs also together with signal functions |
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or breakpoints as shown in the following |
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example program. |
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// in your C user program |
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p1value = P1; |
// read Port 1 input |
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P3 = p1value; |
// write to Port 3 |
Breakpoints that you define in the µVision2 simulator:
bs write PORT3, 1, "printf (\"Port3 value=%X\\n\", PORT3)" bs read PORT1, 1, "PORT1 = getint (\"Input Port1 value\")"
When you execute your C program, µVision2 asks you for a Port1 input value. If a new
Getting Started and Creating Applications |
127 |
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output value is written to Port3, a message is printed in the Output Window - Command page. Refer also to “CPU Pin Registers (VTREGs)” on page 114.
Simulating Interrupts and Clock Inputs
µVision2 simulates the behavior of the I/O inputs. If an I/O pin is configured as counter input the count value increments when the pin toggles. The following example shows how to simulate input for Counter 3:
// in your C user program
T3CON = 0x004B; // set T3 Counter Mode
You may toggle the counter input P3.6 with the VTREG PORT3, i.e. with a signal function:
signal void |
ToggleT3Input (void) { |
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while (1) |
{ |
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PORT3 = |
PORT3 ^ 0x40; |
// toggle P3.6 |
twatch (CLOCK / 100000); // with 100kHz
}
}
View the Counter 3 status with the Peripheral dialog.
Also interrupt inputs are simulated: if a port pin is used as interrupt input, the |
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interrupt request will be set if you toggle the associated I/O pin. |
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Simulating External I/O Devices |
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External I/O devices are typical memory mapped. You may simulate such I/O |
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devices with the Memory Window provided in the µVision2 debugger. Since |
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the C user program does not contain any variable declarations for such memory |
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regions it is required that you map this memory with the MAP command: |
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MAP X:0x1000, X:0x1FFF READ WRITE |
/* MAP memory for I/O area */ |
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You may use breakpoints in combination with debug functions to simulate the logic behind the I/O device. Refer to “User Functions” on page 141 for more information. Example for a breakpoint definition:
BS WRITE 0x100000, 1, "IO_access ()"
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Chapter 5. Testing Programs |
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Assigning Serial I/O to a PC COM Port
The ASSIGN command allows you to use a PC COM Port as input for an UART in the µVision2 simulator. If you enter the following commands, serial I/O is performed via the COM2: interface of your PC. The STIME variable allows you to ignore the timing of the simulated serial interface.
>MODE COM2 9600, 0, 8, 1 |
/*9600 bps, no parity, 8 data & 1 stop bit*/ |
>ASSIGN COM2 <S0IN >S0OUT |
/*ASC0 output & input is done with COM2:*/ |
>S0TIME = 0 |
/*ignore timing of simulated ASC0 interface*/ |
Checking Illegal Memory Accesses
Sometimes it is required to trap illegal memory accesses. The µVision2 access breakpoints might be used together with the system variable _break_. In the following example the program execution stops when the array save_record is accessed outside of the function clear_records.
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Command Input from File
Commands for the µVision2 debugger might be read from file with the INCLUDE command. Under Options for Target - Debug you may also specify an Initialization File with debug commands. Refer to page 102 for more information.
Getting Started and Creating Applications |
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Presetting I/O Ports or Memory Contents
Some applications require that I/O port values or memory contents are set to specific values before program simulation. In the debug Initialization File you may include the commands that are required to preset the simulator. Example:
PORT3 = 0 |
/* set Port3 to zero |
*/ |
LOAD MEMORY.HEX |
/* load hex file contents to memory |
*/ |
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/* use the SAVE command to save memory contents */ |
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Writing Debug Output to a File
The commands LOG and SLOG can be used to write debug output files. You may run the µVision2 debugger in batch files and use a debug Initialization File that contains these commands to automate program test. Refer to “µVision 2 Command Line Invocation” on page 211 for additional information.
>LOG >>C:\TMP\DEBUGOUT.TXT |
/* protocol Output Window - Command page*/ |
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>SLOG >>C:\TMP\DEBUGOUT.TXT |
/* protocol Serial Window output |
*/ |
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>/* Output of the Command page and the Serial Window written to file |
*/ |
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>LOG OFF |
/* stop Output Window protocol |
*/ |
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>SLOG OFF |
/* stop Serial Window protocol |
*/ |
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Using Keyboard Shortcuts |
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View – Options allows you to configure shortcut keys for all menu items. With this dialog you may personalize µVision2 to your needs. For example, you may add a shortcut key to insert/remove breakpoints in an editor window.
NOTE
The assignment of shortcut keys is saved in the file
C:\KEIL\UV2\UV2.MAC.
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Chapter 5. Testing Programs |
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Kernel Aware Debugging
µVision2 supports Kernel Awareness for operating systems with debug DLLs. Refer to “RTX Kernel Aware Debugging” on page 180 for details on testing programs that use the RTX-51 Tiny real-time operating system. RTX-51 Full applications are tested with similar features. µVision2 allows you to add own debug DLLs that display the status information for operating systems or other applications. We will provide an Application Note on www.keil.com that explains how to write user-specific debug DLLs for the µVision2 debugger.
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