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Interestingly I noted that it supports 16GB DDR3 RAM. Since all current ARM cores are 32bit I wonder if they are doing some sort of bank switching to address al
by christkv 14y ago
Interestingly I noted that it supports 16GB DDR3 RAM. Since all current ARM cores are 32bit I wonder if they are doing some sort of bank switching to address all the RAM.
- btian 14y agoApparently some Marvell CPUs have 64-bit address extension http://www.marvell.com/embedded-processors/armada-xp/ http://www.marvell.com/embedded-processors/armada-xp/
- sparky 14y agoMost likely it's something like x86 PAE, where each process has a 32-bit address space and the page table just has a few extra bits to map into a >4GB physical address space.
- kale 14y agoI'm a little outside of my area of expertise, but didn't Intel late model 32-bit chips have a form of larger memory addressing? I thought I read somewhere that there was a greater-than-32-bit memory address setup in x86 architectures, but Microsoft products wouldn't take advantage of it, only Linux and other OSs were able to use it. Even in a modern x86-64 bit architechture, you can do some limited 128 and 256 bit operations. This ARM may have a greater-than 32 bit memory addressing setup, but only support 32 bit opcodes for the main registers.
- theatrus2 14y agoYou're thinking of PAE. It allowed the system as a whole to use more than 4Gib, but it still limited a virtual memory space to 4GiB.
- rlpb 14y agoAs others have said: with PAE. This is included in ARM's Cortex A15 Core, although AIUI Marvell use their own. Further reading: https://en.wikipedia.org/wiki/Cortex_A15 https://en.wikipedia.org/wiki/Cortex_A15 http://www.eetimes.com/electronics-news/4206387/ARM7-40bit-virtualization http://www.eetimes.com/electronics-news/4206387/ARM7-40bit-v...