As pointed out on the Wikipedia page, it is proprietary. As I recall, there were several competing systems in the late 1980s. They combined into the iBiquity system in the 1990s. Recently iBiquity was bought by DTS. I suspect that you cannot purchase the receiver chips without a license from DTS. Chip manufacturers will not sell you a chip that includes a Dolby decoder unless you have a license from Dolby (and similar for DTS). Harold > It seems that the HD radio format adopted in the US is indeed proprietary= .. > In some other countries different formats are used, some of which are ope= n > standards: > > https://en.wikipedia.org/wiki/HD_Radio > > > On Sun, May 28, 2017 at 8:41 AM, Mark Hanchey > wrote: > >> I am interested in learning how HD radio works and is implemented in >> consumer gear and I was able to find >> information on the implementation but was wondering if anyone on the >> list has done any work on the hardware side of things. >> Are there specific IC that are used to receive the signal then a >> separate codec chip or are there IC with all of it integrated ? >> It seems to be a closed format , which I guess is one of the reasons >> that it hasn't taken off as well as it could have. >> >> I found one IC by silabs that appears to receive it but the datasheet is >> more of a sales sheet and it is one of those where you >> have to contact sales for more information. The IC I found was the >> SI4682 and seems to have all the main functions implemented but >> without a datasheet hard to tell. >> >> Thanks >> Mark Hanchey >> >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 FCC Rules Updated Daily at http://www.hallikainen.com Not sent from an iPhone. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .