AVR Register Summary Addresses

[eyeanand]

Hi everyone,

I am learning AVR microcontroller in my embedded system class and while going through the datasheets in the register summary section I am stumbled at one concept.

In the register summary for Addresses $20 to $5F are given in brackets while all the other top addresses do not have a corresponding bracket addresses.

What do these Bracket addresses mean and in which instruction should i be using them.

PS: What I understood through observation is that all ports have been mapped to this address space.. so When accessing ports which address should i use the bracketed or the others.

 

[cl10greg]

The addresses are assigned to different registers. There are special function registers and general purpose registers. The special functions are used for peripherals and memory functionality while the general purpose of open blocks of memory for your use. I am not sure which the bracket represents but if you review the datasheet it should say what it is allocated to.