Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new ta

Assembler is the most obvious language that you'll consider using as you probably won't need to buy any other tools to use it. More than likely the manufacturer will provide an assembler for the chip and you won't need any books as all the instructions are in the datasheet and you just start coding.

This route to programming is very easy but you may be setting yourself up for problems later on as:

1. It is trivial to write short programs.
2. It becomes progressively more difficult to write large programs.
3. It seems to be the best option as it gives the fastest code.
4. It seems to be the best option as it gives the smallest code.

Assembler: Fast & small code

There is no doubt that assembler gives the fastest and most optimized code (your brain is better at optimization than any compiler!) but assembler is difficult – typically you'll spend ten times as long writing assembler as you would writing in a high level language.

Assembler / Compiler Trade off

This is the trade off; to write the fastest most optimized code or to get the task solved more quickly.

Another problem with assembler is that to do even the most trivial task you have to think about every aspect of the code and all implications on registers and register flags.

Even making a microcontroller perform the most trivial task is difficult e.g. for making a loop in assembler you need to think about which register to use and which instructions all the while thinking about how those registers should not interact with the loop register/other registers etc.

Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new tar

1. It is trivial to write short programs.
2. It becomes progressively more difficult to write large programs.
3. It seems to be the best option as it gives the fastest code.
4. It seems to be the best option as it gives the smallest code.

Assembler: Fast & small code

There is no doubt that assembler gives the fastest and most optimized code (your brain is better at optimization than any compiler!) but assembler is difficult – typically you'll spend ten times as long writing assembler as you would writing in a high level language.

Assembler / Compiler Trade off

This is the trade off; to write the fastest most optimized code or to get the task solved more quickly.

Another problem with assembler is that to do even the most trivial task you have to think about every aspect of the code and all implications on registers and register flags.

Even making a microcontroller perform the most trivial task is difficult e.g. for making a loop in assembler you need to think about which register to use and which instructions all the while thinking about how those registers should not interact with the loop register/other registers etc.

Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new ta

Assembler / Compiler Trade off

This is the trade off; to write the fastest most optimized code or to get the task solved more quickly.

Another problem with assembler is that to do even the most trivial task you have to think about every aspect of the code and all implications on registers and register flags.

Even making a microcontroller perform the most trivial task is difficult e.g. for making a loop in assembler you need to think about which register to use and which instructions all the while thinking about how those registers should not interact with the loop register/other registers etc.

Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new ta

Even making a microcontroller perform the most trivial task is difficult e.g. for making a loop in assembler you need to think about which register to use and which instructions all the while thinking about how those registers should not interact with the loop register/other registers etc.

Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new ta

Assembler: Problem - changing the target

Another difficulty is when you change from one microcontroller to another (even in the same device family) the assembler instructions may be changed e.g. more instructions to improve microcontroller performance. So you will have to learn an entirely different instruction set when moving either to a new target microcontroller or moving to a different device within the same family i.e. code re-use is not possible unless you stay with one microcontroller (or devices with a similar internal architecture).

High level languages

HLL: Retarget

Retargeting code to another microcontroller is easier since the HLL will know the details of the new target i.e. instruction set, fuses etc. All you need to worry about is the specific differences between the different microcontrollers (in the same family this will be setting up the internal peripherals).

The important point is that the HLL takes care of the assembler code needed to do the job.

HLL: Easy to understand.

The most useful aspect of a high level language (HLL) is that the language is written in a form you can easily understand – there are no cryptic assembler commands that you have to remember and most commands are made up of several machine code instructions – saving you coding effort (often there are built in libraries of code e.g. LCD driver, Serial port driver, I2C driver etc

So the HLL makes it easy to write code as it generates the correct assembler for the target microcontroller.

HLL : Whitespace

You can also make use of white space (areas of no code) to separate out the various operations within the program – typically assembler code is just one great big list that is really very difficult to read – I know there are comments but you need to comment almost every line so that someone else can

understand the code.

HLL: Task splitting

One of the best features o