Other Parts Discussed in Thread: TAS5805,
Tool/software: Linux
We adapted TI's TAS5805 Linux driver to get to work with the TAS5825. Only moonier changes were needed. We also created a simple prototyping board that enables us to connect our processor to the TAS5825 via I2C and I2S. We provide 3.3V for digital power, and 12VDC for analog power. We can communicate with the chip via I2C, including setting registers and reading register values. We also created a minimal configuration. The driver asserts this configuration when it is loaded. However, no matter what we do, we do not get any switching on the speaker outputs.
The !mute pin is asserted high. The !shutdown pin is asserted high.
Status Register 0x03 reports a value of 0X03 when music is present on I2S (this indicates the chip is in play mode) and 0X0B when music is absent (this indicates mute-on + play mode). We are not externally controlling the muting of the chip, so the change from mute-off to mute-on is presumably being done by the chip, not us. Nevertheless, it seems to indicate that the chip is aware of the presence or absence of an I2S stream.
Interestingly, the fault registers report faults but we cannot figure out what the faults are due to:
Fault Register 0x70 reports 0x01, which indicates a right channel over current fault.
Fault Register 0x71 reports 0x04 which indicates a clock fault.
Our configuration is as follows, written to the chip in the order shown:
Register |
Value |
0x01 |
0 |
0x02 |
0 |
0x0F |
0 |
0x28 |
0x39 |
0x29 |
0 |
0x31 |
0 |
0x33 |
0x03 |
0x34 |
0 |
0x50 |
0 |
0x03 |
0x03 |
You might wonder if we have tried the TAS5825EVM eval kit, and the answer is that we have ordered it but have not yet received it.
Finally, for the moment, I would like to point out that the data sheet documentation for Table 11 is not correct. It describes bit 3 of register 0x28H as having four bits of information. Clearly four bits cannot fit into one bit! We looked at Table 11 in the data sheet for the TAS5805 and it makes sense. We used the values from the TAS5805 data sheet to set register 0x28 in our TAS5825.
Any help you can provide would be most appreciated.
Respectfully,
Robert Seliger
WHIM LLC