order of buttons/encoders on shift registers

[illogik]

Hey, just a quick and simple q.

Are the din tables for buttons/encoders in TK's diagrams ordered so they give the best performance? For instance; on mbseqv2 the encoders/gp buttons are all at the end of the SR chain; is this just a personal choise or does it have an (important) other reason?

cheers, marcel

[raphael]

As far as I understand the MIOS sourcecode all DINs are scanned every ms (search for IRQ_Timer1). So no difference if a button is first or last in chain.

I think Thorsten arranged them for easy wiring in his own boxes  ;)

[Synapsys]

Hi,

Raphael is correct. The timer 1 interrupt handler (source in mios_isr.inc) calls the MIOS_SRIO_Tick (source in mios_srio.inc) routine every millisecond. This routine processes all the DIN and DOUT shift registers that are installed in the system. The timer 1 interrupt handler then calls the MIOS_ENC_Tick (source in mios_enc.inc) routine. This routine checks the DIN data just read by the MIOS_SRIO_Tick routine and processes any DIN change related to the encoders.

As a result, in terms of performance, it makes no difference where the physical buttons and encoders are attached to the DIN chain. Of course each encoder must be connected to two adjacent pins in the chain. ;)

Regards,

Synapsys

[illogik]

fanx mates!