Le samedi 20 septembre 2014 16:42:31 UTC-4, Charles Steinkuehler a écrit :
>
> On 9/19/2014 6:39 PM, Cedric Malitte wrote:
> >
> > I do coding for microchips and I thought ( beat me ) that the pruss
> would
> > behave the same concerning IOs, I mean direct access.
>
> It does, if you use the direct PRU inputs (ie: read register R31).
>
> It's when you use the GPIO registers via the SoC interconnect that reads
> become very slow.
>
> --
> Charles Steinkuehler
> [email protected] <javascript:>
>
Thanks Charles, I think I got it !
I will try tomorrow if I got time, but should look like this:
MOV r3, 0 // Sensor_1 and Sensor_2 16 bits data
MOV r4, 0 // Sensor_3 and Sensor_4 16 bits data
CLR r30.t14 // CS low
MOV r0, 0 // bit counter
LOOP1:
SET r30.t15 // CLK high
MOV r2, r31.b0 // Read in the data
QBBC ChkSensor2, r2.b0.t0 // if r2.0, set r3.0
SET r3, 0
ChkSensor2:
QBBC ChkSensor3, r2.b0.t1 // if r2.1, set r3.15
SET r3, 15
ChkSensor3:
QBBC ChkSensor4, r2.b0.t2 // if r2.2, set r4.0
SET r4, 0
ChkSensor4:
QBBC EndCheck, r2.b0.t3 // if r2.3, set r4.15
SET r4, 15
EndCheck:
CLR r30.t15 // CLK low
QBEQ DataDone, r0, 15
RotateData:
LSL r3, r3, 1
LSL r4, r4, 1
ADD r0, r0, 1
JUMP LOOP1
DataDone:
SET r30.t14 // CS high
I could also do bitmasking for the data in, as timing should be equal
whatever the bit value is.
I'll chek what I have on the scope and I'll decide later.
Regards,
Cedric
--
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