On Sat, 3 Sep 2011, andy pugh wrote: > Date: Sat, 3 Sep 2011 11:52:02 +0100 > From: andy pugh <[email protected]> > Reply-To: EMC developers <[email protected]> > To: EMC developers <[email protected]> > Subject: Re: [Emc-developers] [Emc-commit] v2.5_branch: Don't assume that the > firmware declares ioports first. > > On 3 September 2011 06:20, Sebastian Kuzminsky <[email protected]> wrote: > >> Also, don't assume that there are never more than 8 SSerial MDs. >> Granted, there probably are not, in any sane config. > > Pete has said that there never can be more than 8 (I have forgotten > the reason) and that 4 is the current limit as no card has more than 4 > connectors.
The current limit is 4, just because of the way the sserial modules are addressed (they use 0x40 address space per module so with the current limit of 0x100 per module type, there is only address space for 4) This is not related to connectors (you could have 8x 1 channel sserial modules on a single connector with a 7I44) This is not as silly as it sounds, the sserial module is not all hardware, it has code that runs on a little uprocesssor so every operation does take noticeable time. There is only one processor per module, so if you wanted better performance, you might want say 2 sserial modules one one connector with 4 channels each instead one one module with 8 channels. Whether this is important practically I dont know, current sserial performance with SSLBP firmware is about 3 uSec delay/channel + 1 usec max jitter from host DOIT to start of packet transmission (so 25 uSec for the last channel of a 8 channel module with all channels active) this could be cut to 13 uSec with a dual x4 configuration with the same daughtercard > > However, even given that I ought to bounds-check the index. > > Actually, while I couldn't sleep last night it occurred to me that a > better approach would be to walk the list once for ioports, then walk > it again for other functions. > > I wonder if I should re-do the change? > > -- > atp > "Torque wrenches are for the obedience of fools and the guidance of wise men" > > ------------------------------------------------------------------------------ > Special Offer -- Download ArcSight Logger for FREE! > Finally, a world-class log management solution at an even better > price-free! And you'll get a free "Love Thy Logs" t-shirt when you > download Logger. Secure your free ArcSight Logger TODAY! > http://p.sf.net/sfu/arcsisghtdev2dev > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Special Offer -- Download ArcSight Logger for FREE! Finally, a world-class log management solution at an even better price-free! And you'll get a free "Love Thy Logs" t-shirt when you download Logger. Secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsisghtdev2dev _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
