Summary of RCEN fuse programmer using AT90S1200A microcontroller
This article describes a standalone programmer designed to enable or disable the internal RC oscillator fuse bit on AT90S1200 microcontrollers, which standard serial programmers cannot modify. The project utilizes Herbert Dingfelder's circuit and source code as a foundation to allow users to program this specific fuse in parallel mode, facilitating the activation of the ~1MHz internal oscillator.
Parts used in the RCEN Fuse Programmer:
- AT90S1200 microcontroller
- Internal RC oscillator
- Parallel mode programming interface
- Herbert Dingfelder's rcen_blower circuit
- Source code from rcen_blower
Introduction:
As you know the AT90S1200 microcontroller includes an internal RC oscillator that is disabled by default. If you want to change it (enable or disable) you must to program it with parallel mode. The most programmers work on serial mode that is not possible to program this fuse bit (RCEN).
With this stand-alone programmer you can enable or disable the internal RC oscillator that works at ~1MHz.
The circuit:
The circuit is based, on the most of the parts and source code, to Mr Herbert Dingfelder’s rcen_blower (http://www.dl5neg.de/rcen_blower/rcen_blower.html).
For more detail: RCEN fuse programmer using AT90S1200A microcontroller
- What is the default state of the internal RC oscillator?
The internal RC oscillator is disabled by default. - Can standard serial programmers change the RCEN fuse bit?
No, most serial programmers cannot program this fuse bit. - How do you enable or disable the internal RC oscillator?
You must program it using parallel mode. - What frequency does the internal RC oscillator work at?
It works at approximately 1MHz. - Does this project use a different microcontroller than the target?
The article implies the programmer uses an AT90S1200A based on the provided link title. - What is the basis for the circuit design?
The circuit is based on parts and source code from Herbert Dingfelder's rcen_blower project. - Why is a stand-alone programmer needed for this task?
A stand-alone programmer is required because standard tools operate in serial mode which lacks access to the RCEN fuse bit.
