I'm trying to build my own Hi-Fi system. So, I recently ordered this Japanese DSP that's able to process Dolby audio. I was all excited until the part had arrived and I found something in the datasheet later.


In particular, I saw that they were kind enough to provide a description of the list of commands they offered, but not so kind enough to describe how to actually instruct the DSP of these commands.

enter image description here

My question is, is there a way to instruct these commands to the DSP chip just based on the information I have, or is it just dead weight for now?

Things I've tried:

  • Contacting the manufacturer multiple times as they've mentioned in the datasheet with no response from them.
  • Search online for the Software Application note / Manual that's described in this doc with no luck.

The MPU I'm trying to use to talk to this DSP is an Arduino Uno if that helps.

Any help is much appreciated.

  • \$\begingroup\$ Do you have access to a device that uses this chip? If so it may be possible to listen on the command bus and reverse engineer the protocol. If not, I'm not sure there's much to go on here. \$\endgroup\$ – Nate Strickland Apr 18 at 23:17
  • \$\begingroup\$ Notes : In respect to detail command information, request New Japan Radio Co., Ltd. and permission of a licenser (Dolby) is required. \$\endgroup\$ – Sunnyskyguy EE75 Apr 18 at 23:38
  • \$\begingroup\$ Does this help any? \$\endgroup\$ – jonk Apr 18 at 23:50
  • \$\begingroup\$ @jonk That datasheet seems even less detailed than the one the OP is working with. \$\endgroup\$ – duskwuff Apr 19 at 7:08
  • \$\begingroup\$ @duskwuff It has some information missing from the other one. I was curious if it added anything. \$\endgroup\$ – jonk Apr 19 at 7:09

This is how it really works, they can"t give you details as it is running licenced intellectual property from someone else. At least you would need an NDA with them to prevent you from publishing non-public information. Also they might not even get back to you as you are a single hobbyist without NDA so it is a waste of their time talking to and supporting someone that buys one chip. It would be different if you were a company making a product that sells even 1000 chips per year. I don't know the details and it was very long ago, but I have worked with NJU DSPs.

  • 1
    \$\begingroup\$ I get that, I have a simple question though - do I simply pass these commands in serial? For example, "SET_TASK_COMMAND", <some value>. I ask this because I vaguely know the values to pass for some of these commands. I would like to know if it can be just passed on serial? \$\endgroup\$ – dsignr Apr 19 at 16:26
  • \$\begingroup\$ You don't have the programming reference manual, so you don't know what the command parameter values mean, or even how many parameters each command needs. \$\endgroup\$ – Justme Apr 19 at 16:28

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