About the deviceThat device is Afatech AF9035 reference design. It has two independent tuners aka dual tuner model. Used RF tuners are Fitipower FC0012. Device uses chipset vendor reference design USB ID 15a4:1001.
I would not like to thank device vendor Cabletech as they didn't even answered my queries about sample device. Instead thanks to some anonymous Linux user who donates his device for driver development.
Device is supported under Linux starting from the Kernel 3.9.
Cabletech URZ0185 teardown
Key components:Afatech AF9035
PCB top side
|AF9035 and AF9033|
Black component, which is partially top of both tuners, is IR-receiver for remote controller. Piece of tape between RF-tuner and IR-receiver is avoiding possible short circuit(?).
Black chip most near USB-connector is AF9035. I am not going to AF9035 details now as I have explained it quite carefully earlier. Lets still mention it is chip that integrates USB-interface and DVB-T demodulator. Demodulator integrated is AF9033. That version of AF9035 has also pins to connect slave demodulator using serial TS.
There is small metal box, crystal, between AF9035 and USB-connector. It offers 12.000 MHz clock source for AF9035. 12.000 MHz is very standard USB reference clock.
The most centre big chip is AF9033 DVB-T demodulator. It is slave demodulator for AF9035 offering 2nd tuner. Note that AF9035 itself integrates one AF9033 - so there is two AF9033 logically on that device. AF9033 gets clock from AF9035, own crystal is not needed for that kind of dual configuration. There is clearly visible 4 + 2 wires between AF9033 and AF9035. That four wire bus, going through resistor network RP1, is most likely serial TS. Two wires going through resistors R23 / R24 is likely I2C bus. TS bus feeds data and I2C is used for control.
IR-receiver is connected to AF9035. First FC0012 is connected to the AF9035 and second one to AF9033, both TS and I2C buses.
PCB bottom side
|Bottom side of PCB|
36.000 MHz crystal is for FC0012 RF-tuners.
PCB has printings "94-V0", "12-13", "DK-5902 V1.0", "iTE Technologies, Inc". Last one reveals it is clearly reference design. Originally AF9035 was made by Afatech and later Afatech was acquired by ITE Technologies.
|AF9035 FC0012 dual tuner block diagram|
It took something like 60 hours of work and result was only about 100 lines of code. Sometimes Kernel coding is very slow at the unit of used hours for lines of code, especially when hacking with complex embedded hardware.