Richard, I think you will find answers to many of your questions
by reviewing my two previous posts on the PLX 9080 I2O product
announcements. Recall that the i960 RP/RD is the ONLY single-chip
IOP solution, and it INCLUDES an IxWorks license. If an OEM wanted
to implement their own IRTOS for the i960 RP/RD, WIND would still
get their royalty. If the OEM chose a different processor for their
IRTOS implementation, they would lose the advantage of a single-chip
solution. The i960 RP/RD not only provides a single-chip IOP, it
also includes a full PCI-to-PCI bridge, allowing the PCI bus to be
extended beyond its normal slot capacity. This combination of
functionality is REALLY hard to beat! Until another manufacturer
comes out with a comparable device, there is just no compelling
reason for an I2O design NOT to choose the i960 RP/RD. Intel will,
of course, continue to improve the performance of the i960 Rx, so
any competition will be hard pressed to catch up. I would expect
Motorola to enter the battle, but they didn't join I2O until a
couple of months ago, so I can't see any concrete products from
them until mid-1998 or later. I really think Intel caught the chip
vendors off guard with I2O - nobody realized it was big until it
was big ;-), with Intel already firmly entrenched.
On top of all this, there is the issue of device driver portability.
Remember that the I2O IRTOS provides the device driver framework -
the functionality and corresponding API that I2O device manufactures
write their "write-it-once" device drivers for. This feature of I2O
is its biggest "win", next to pure I/O throughput/performance. If an
OEM implements an IRTOS on a non-i960 processor, the I2O device manu-
facturers would have to maintain versions of their I2O device driver
software for the "other" processor(s), in addition to the i960
version. This would be an extra expense for them, and I don't see
them bothering to support other IOP processors, unless those IOPs
somehow gained considerable market share.
With regard to the "real-time" requirement in I2O, think about RAID -
synchronized reads and writes across multiple hard disks. LAN
interfaces have "soft" real-time requirements to handle large numbers
of communications protocol timer events. As I2O goes forward and
encompasses more device types, we will see stepper motor control and
A/D-D/A sampling, etc. Also, keep in mind that I2O requires: small,
fast, efficient, and RELIABLE - all hallmarks of the leading RTOS!
Hope this helps!
-Dave Lehenky |
