Once you have added ISD51 to your program, you must configure the
µVision IDE and Debugger for communication with the 8051 target
Start the 8051 application on the target system before you
start the µVision Debugger.
µVision, select Project — Options for Target — Debug: Use: Keil
ISD51 In-System Debugger.
Enable Load Application at Startup so that the µVision Debugger
loads the symbolic information for your 8051 program.
Disable Go till main. Your user program is started by the
hardware reset of the 8051 target system.
Click Settings to open the ISD51 Driver Settings dialog
and configure the ISD51 Options
COM Port Settings
These options configure how the PC serial port communicates with
your target hardware.
Port: PC COM port used to connect to the 8051 target
Baudrate: Communication baud rate with the 8051 target
RTS and DTR: Level on the RTS or DTR lines of the
Always High (Active): Signal is always active during
µVision Debugger communication.
Always Low (Inactive): Signal is always inactive
during µVision Debugger communication.
Reset High 500ms (Active): Signal is active for 500
mSec on Reset Command of µVision Debugger.
Reset Low 500ms (Inactive): Signal is inactive for
500 mSec on Reset Command of µVision Debugger.
Reset Pulse: 500ms High, 10ms Low: Signal is active
for 500 mSec then inactive for 10ms on Reset Command of µVision
Reset Pulse: 500ms Low, 10ms High: Signal is
inactive for 500 mSec then active for 10ms on Reset Command of
The ISD51 driver implements memory caches to speed-up screen
Disable the cache options to view actual (un-cached) values of
DATA (and SFR), IDATA, or XDATA space when you halt program
execution. This way you can be certain you are viewing the current
values of I/O ports, timers, or memory-mapped peripherals.
- Enable the cache options to obtain maximum performance.
Code Breakpoint Options
This option selects whether or not ISD51 uses software
breakpoints, hardware breakpoints, or a combination of both.
If your target 8051 device does not support hardware
breakpoints, you must select software breakpoints only.
If your target 8051 device supports hardware breakpoints, you
must use software breakpoints when no hardware breakpoints are
Verify if Application in ROM is identical to current
Project: Selects whether or not the µVision ISD51 Debugger
Driver compares the program code in the 8051 target with the
program code of the current project when initializing ISD51
communications. You may disable this option to speed-up the
connection time of the debugger with the target system.
If you do not wish to compare the entire application range or if
your application contians configuration areas that should be
excluded, you may configure the verify address range with
CMP_START and CMP_END in the ISD51.H header
This box displays the version number and other status information
when the µVision Debugger connects to the ISD51 running on the 8051
target system. You may check this information when you open the ISD51
Driver Settings dialog during debugging.
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