e_write/e_read confusion - Epiphany ram

[AndyC]

[notzed]

e_alloc() only maps memory in the shared area.

You're reading/writing to completely different locations, not surprisingly since the arguments are completely different objects.

[AndyC]

Hi,

Thanks for the info.

The e-bandwidth-test example code tests host to ERAM speed using this method, is this a different ERAM then?

[notzed]

[AndyC]

Hi,

It was me getting confused with the naming conventions.

As far as I see it there is:

1. Host Ram
2. Shared ram
3. Epiphany local ram

I took ERAM to mean 3 where as far as I can see it is actually 2.

Cheers

Andy

[notzed]

Yes the object in your example called "eram" is in 2, the shared memory.

Hence I would give it a more accurate and mnemonic name, like "sram" and reserve the mnemonic "eram" for e(piphany) ram.

[sebraa]

Why not use the official terms?
- Host Memory (not really important when programming for the Epiphany, since it can't access it)
- Shared Memory or Shared DRAM (or External DRAM or DRAM, but these suggest different things to me)
- Local Memory or SRAM
They are used in the official documentation and in the linker scripts. ERAM then means "External RAM".

[AndyC]

Hi,

ERAM is not defined in the documentation at all as far as I can see.

[notzed]

[sebraa]