My problem is that I don't know how to handle the addition when it gets out of the 8-Bit range. My program runs with small Hex numbers like #02h + #05h but not with higher numbers like #0A9H + #0B5...

how to enable external interrupt of 8051?

Almost all the simple 8051 programs I have seen so far ends with the code LOOP: SJMP LOOP. From my understanding I think the above instruction creates an infinite loop by calling the same instruc...

I'm hoping to optimise an implementation of SHA-1 for an 8-bit MCU (8051-based). The input data is only 8-bytes, so I wonder if something could be done to improve this macro: #define S(x,n) ((x &l...

In pic microcontroller TRIS register determines whether port would act as input or output and PORT register would determine the content, what should be written (in case of output) or read (in case ...

If I ever want to create a finite state machine in 8051 assembly, I'll need an efficient equivalent of C switch() expression. [for this question, let us disregard the fall-through behavior, both r...

I've inherited a 10K-line program written in 8051 assembly language that requires some changes. Unfortunately it's written in the finest traditions of spaghetti code. The program--written as a sing...

I am new at embedded system programming. I am working on a device that uses an 8051 chipset. I have noticed in the sample programs that when defining variables, sometimes they use the keyword xdata...

Could someone please tell me if it's possible to burn an 8051 microcontroller with a C++ program? I've tried searching about it online but can't seem to find out for sure if it's possible or not. ...

I am trying to use Xcode as an editor for microcontroller code. I want to use the Build, Run buttons. How can i use those to trigger a script that compiles the program ? I already have a script tha...

I've done some researching on bit addressable microcontrollers. The only one that came across in my path is the Intel MCS-51(wiki page) which is still used very commonly today... I was wondering if...

I see "printf" instruction in sample codes of c language for microcontroller particularly in 8051. Since microcontrollers has no fixed output display what is the use of the "printf" instruction?

I'm writing a program for a 8051 microcontroller. In the first part of the program I do some calculations and based on the result, I either light the LED or not (using CLR P1.7, where P1.7 is the p...

What are the advantages of using ATmega32 than other microcontrollers? Is it better than PIC, ARM, and 8051?

If I have a int32 type integer in the 8-bit processor's memory, say, 8051, how could I identify the endianess of that integer? Is it compiler specific? I think this is important when sending multyb...

I'm supposed to write a program that will send some values to registers, then wait one second, then change the values. The thing is, I'm unable to find the instruction that will halt operations for...

For learning purpose i intend to start building a 8051 microcontroller emulator. I am comfortable programming in C/C++/C#. This is no class project etc but a learning initiative from my side. I di...

I am making an 8051 microcontroller communicate wirelessly with a computer. The microcontroller will send a string to its serial port (DB9) and the computer will receive this string and manipulate ...

I'm working on a project on an 8051 where every byte counts. As such, I am using some global variables where I normally wouldn't. The normal method of passing pointers into a function adds too much...

I need to optimize code to get room for some new code. I do not have the space for all the changes. I can not use code bank switching (80c31 with 64k).