[littletiger008]

hi, experts:
Is there any offical documents describing the difference between cortex-A7 and cortex-A9?

best wishes,

[ttfn]

If there is such a document I haven't seen it, but I suspect it does exist

Headline differences (from a software perspective)

• - A7 supports the Virtualization and System Timer extensions to ARMv7, the A9 doesn't
• - A9 has hardware coherency management between the different cores in the processor. A7 additionally supports system coherency management (e.g. An A7 + A15)
• - A9 MPCpre has a built in interrupt controller based on GICv1, on the A7 the IC is optional and based on GICv2 (mainly adds Virtualization support)
• - A9 implements VFPv3, the A7 VFPv4. Basically this means he A7 supports Fused MAC operations, but the A9 doesn't
• - A9 has built in watchdog, the A7 doesn't

May seem like a big deal, but mostly these differences would only be important to bare-metal or kernel code.

Edit: trying to fix formatting

This post has been edited by ttfn: 05 January 2013 - 04:36 PM

[isogen74]

Presumably based on the numbering (in general bigger core number = faster) the A9 will run code faster than the A7, but I'm not actually sure (not managed to lay my hands on an A7 yet).