Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Bootloader for PIC16F877.....Help Needed Urgently

Not open for further replies.


Junior Member level 3
Dec 16, 2002
Reaction score
Trophy points
Activity points
I have not been able to download the Bootloader Hex file onot a PIC16F877 successully. The problem that I am facing is:

I am using ALL-11 Programmer manufactured by Hi-Lo Systems. Whenever I upload a file to be downloaded into the microcontroller I am required to give its type. I selected INTHX8M and then there was another option which read as follows:
Unused Bits
(i) Dont Care (When I use this option and program the microcontroller that file is successfflly transferred to the robot but the problem is that the red and green leds of the robot are turned "ON" in pgm mode as well as in exec mode. Moreover whenever I try to use the Hemisson Uploader after serial connection it doesnt detect the robot. )
(ii) 00 (Nothing happens. No led is turned ON. Rather the robot behaves very unexpectedly and its motors start rotating without any fixed pattern and then stpo after some time.)
(iii) FF (When i use this option the program is not transferred correctly as when i compare the programmer buffer with the memory on the microcontroller it gives some mismatches in the memories. e.g. if for some bits the buffer of programmer reads FF FF FF then the buffer of the microcontroller returns 3F 3F. )

Moreover when I totally erase the memory of the robot even then the memory is not all FFFF's rather it is like 3F 3F 3F in the start and then the rest behaves OK.(Some zeros in middle 4200 range and then all FFF's. )

Could you please help in this regard. I am really in trouble and really tired of this whole thing.

Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to