Re: [ts-7000] EP9302 Instruction set timings

["Martin Guy" <>]

2008/3/1, Kevin Cozens <>:
> This just means my guess as to the number of cycles for subs and bne was
>  somewhat optimistic.

I just checked the kernel code and results. It (linux-2.6.22.3) uses:
ENTRY(__delay)
                subs    r0, r0, #1
                bhi     __delay
                mov     pc, lr

On armv4t CPU, this reports the number of BogoMIPS as a fraction of 1%
under half the CPU clock frequency, which indicates that it is taking
4 cycles per loop (1 + 3, I guess).
By comparison, the armv5t cores report BogoMIPS as a-f-o-1%-u the CPU
clock frequency.

The ts7250 has an armv4t CPU, so I guess 4 cycles is your answer.
(This also explains why BogoMIPS are so Bogo :)

    M


 
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