Hello all,
I'm working with the SRC4382, and I'm trying to read back the ratio from the SRC. I use a PCB with some connectors for AES and S/PDIF. A PIC is the Host for setting the registers via I2C. PORTA is an output, PORTB is not connected.
Register 0x32 and 0x33 should show the ratio, but they both return all zeroes(0x00). The datasheet mentions: "These registers can be read back any time the RDY output is low.".
The ~RDY output is HIGH, and this will cause that register 0x32 and 0x33 are zeroes, as the SRC has not estimated the ratio yet.
The problem is that the ~RDY pin (pin 15) won't go low in any case.
I supplied an AES3 32, 44.1 or 48kHz signal via an Audio Precision1 (AP1), and the resampled signal is returned to the AP1 in the proper sample rate. I get the proper signal back. So the systems works, but PLL1 or PLL2 does not get into "slow" mode. The ~LOCK pin (pin 11) is low, meaning that PLL2 is in lock. This suggests that PLL1 is not working properly. I also tried this with an S/PDIF signal, but this does not change anything.
If PLL1 is not working properly the input data would not be sampled properly and there would be no output. So PLL1 must also be working.
I'm stuck now, as I have checked everything I was able to. All error registers show that there are no errors.
I use a 24.5760MHz master clock, the register settings I used are shown below:
Register Setting Meaning
0x01 0x3F Power: Power up all
0x07 0x10 TX control1: TX Input Data Source = DIR
0x09 0x06 TX control2: Valid bit and User data via DIR
0x0B 0x33 Interrupt masks: All interrupts on
0x0D 0x08 Reciever control: Use RX1, use MCLK
0x0F 0x22 PLL1 config: P=2, J=8, D=0 (24.576MHz clock)
0x10 0x00 PLL1 config:
0x11 0x00 PLL1 config:
0x2D 0x02 SRC Control1: Use DIR
All other registers are 0x00.
The ~RDY output is directly connected to the MUTE input, this should not cause problems. Weird thing is that the output signal via DIT is not muted.
I have checked the physical connections for errors, and there are none.
What else can I check to see what is going on? Has anyone experienced problems like this?
Thanks in advance,
Justin Vis
Edit: I have disconnected the ~RDY pin from the MUTE pin, with no result.