Does the 975 remote support the 2008-era Pioneer plasma displays? Specifically the PDP-6010FD. I don’t see a code in the manual, and tried those for other device types to no avail. Would be nice to eliminate the Pioneer remote as I only use if for the built-in OTA tuner.
Did you try 0051, 0201, 0951, 1091, 1491, 1571, 1651, 1831, 1881, 1961, 2151, 2711, and 2801 listed under TV, Panasonic? If so, then your TV's IR hex codes are not accessible via the Model 975's remote.
If you mean the AV processor, and not the chipset in the remote, that is not how it works. The roughly 4 digit code you enter into the remote tells it how to transmit the IR signal via pulse width modulation and which carrier frequency to operate on. The processor simply receives the IR. You may find this helpful if you wish to know more about remote control via IR: https://learn.adafruit.com/ir-sensor/ir-remote-signals . I'd note, these remotes were never intended to compete with Logitech Harmony remotes; they are not learning remotes, will not have nearly as many options for number of devices to control, and do not have a continually update-able database.