The MON-51 8051 Rom Monitor is an executable program for the 8051 family of microcontrollers. Placed at the core of an application, it provides efficient scheduling by driving:

• Step by step or continuous execution

• Breakpoints

MON-51 is easy to implement and allows the programmer to debug his/her application.

MON-51 provides support for any compatible derivatives of the 8051. However, it needs a communication link between the development environment (RIDE) and the target where the application is running. This link is usually achieved via the UART that is present on every compatible derivative of the 8051 and consequently this UART cannot be used elsewhere in the application. Hence the use of the ROM-Monitor has an effect on the application. If an application needs to use a UART, it cannot be the same one as used by the ROM-Monitor.

MON-51 consists of two parts:

• The libraries (not accessible to the programmer).

• The part used for communication between RIDE and the target board. The source files of this part in 'C' and Assembler are provided to allow the programmer to migrate the ROM-Monitor to a specific board/application.

The contents of the different memory spaces of the current application can be visualized using the different windows of RIDE.

It is possible, with the MON-51 ROM-Monitor, to modify the content of DATA, XDATA, SFR or BIT memory space. However the SFR registers and bits associated with the UART used by the monitor must never be modified.

The ROM-Monitor is downloaded at the same time as the main program code. It is directly managed by RIDE and allows facilities such as 'step-by-step' execution and inspection of variables. If the target board can 'write to CODE space', advanced features such as 'line-by-line execution' or code breakpoints are also possible.