i have a MCF5307 based custom board set with 45Mhz oscillator, 90Mhz CPU CLOK (x2) and 45 Mhz BUS_CLK (div. 2).
I am measuring through oscilloscope the length of some basic instructions (in time) to see if the execution speed is really 90Mhz, since i have some doubts on this.
move.w #AAAA, (ADDR_PADAT) ( i am producing a square wave on PADAT)
For this single "move.w #xxx, (A)" i get 360ns with cache disabled, or 132ns with cache enabled or internal dram.
This instruction should take 2 clocks, so i was expecting 11,1 nsec x 2 = 22 nsecs.
Then i measured, always executing from internal ram, a single short jmp. It takes 50nsecs.
But i was ecpecting 11nsecs (1 clock).
Then i measured the output clock on PSTCLK (delayed CPU clock). It is 90Mhz, as expected.
Can someone maybe elucidate me on this long instruction timings ?