Epiphany address space

[Amir]

Hello

It's written that epiphany has 32 bit address space. I want to know that what does this address space contain? Does it contain addresses of the cores and the local memory banks? And does it has some size?

And also, does 32 bit address means that each core or a memory location's address would be 32 bit long?

[ysapir]

32-bit address space means that you can uniquely access about 4 billion (2^32) memory locations, usually (and specifically in the Epiphany's case) made of 8-bit bytes (that is, 4GB of memory).

Within this space are included the core's local memory (32KB RAM and Memory Mapped Registers), the neighboring cores' memories and any memory location external to the chip that shares the same space.

Note that each core "has" its own 1MB slice of the 4GB space which is regarded as "local" memory, and can be accessed (by that core) either using its "global" (32-bit) address, or a "local" (20-bit) address. Addressing other cores' memory is done using the global address. Addressing external memory is done using global addresses as well.

[Amir]

Thanks!

I just want to know that what is the difference between a global address and a local address? And why global address is 32 bit and local address 20 bit?

[Amir]

And also does each core has its own unique address that is a part of the address space?

[hewsmike]

[Amir]

Thanks Mike...
I want to know that where is the core's address stored? In the address space? And what else is stored in the address space? And what is global and local address?

[hewsmike]

[Amir]

Got it

But there is one thing that I am not getting, and that is does the epiphany chip and all the other components of the parallella share the same memory space?

[hewsmike]

[Amir]

Thanks a lot!