Hi Danial. The actual silicon cost, or mfg'd cost is not the determing factor for semi resales. It is the IC mask set design time and cost. Complex devices may have as many as 20 or more mask sets and thus define several hundred thousand to millions of transistors. Each mask set requires one exposure/cook/cleaning cycles to produce the end device. All silicon die costs are asymptotic about 1-3 dollars, with the packaging costing another 2-15 dollars depending upon how many pins the package has and the material the package is make from - plastic or ceramic.
The complexity of design represents the difficulty of duplicating the design by another manufacutrer. Thus while mfr X is the only source; what the market will bare is the determining factor regarding resale pricing. When a second mfr, say, mfr y goes through the trouble, and time - may take up to 18 months - to duplicate, identically, the device, then competetive pressures determine the device resale. Competition causes device prices to decrease and gross margins to shrink.
There are two philosophies regarding creating devices. If you are there first you define everything, pin definitions, timing, programming...ect. If you are coming along second, you have a choice; second source the existant device exactly, whereupon you can potentially sell into all existing sockets, and generate immediate revenues, but with a declining competively driven sales price; or substantially improve the design, whereupon you can attempt to attract improved designs, a very difficult task, but not quite as difficult as paving the original path.
SCSI works by accepting high level command blocks and executing them automonously. It only notifies the processor when it requires attention. The theory is that the processor is left free to do other things while the SCSI device is executing on it's own the desired command. Thus the processor is notified only when some additional action is required by the SCSI device.
Mike |
