Using the EVM board as a SigmaDSP ADAU1761 development platform with SigmaStudio

The EVM board uses an ADAU1761 for the analog I/O as this maintains compatibility with the Analog Device's A²B EVM boards.  If not using theClockworks EVM board can be used as a SigmaDSP development platform, and the A²B module header on the Clockworks EVM provides easy access to the I²S lines if needed to interface with your own hardware.

The EVM has a 10 pin .1" header for attaching the USBi pod to the board.

With the A²B module removed the ADAU1761 will need to be supplied with its master clock (12.288 MHz is what is normally used).  There are two ways to do that:

1. Populate the DNP locations for the oscillator, series resistor, and decoupling cap.  The advantage of this is the parts are now part of the board. The disadvantage is if you want to use the board for A²B development again you will need to remove the parts.
2. Add an oscillator that plugs in to the auxiliary connector for power and one pin in to the module socket.  The advantage of this is its's trivial to return the board for use with an A²B module.  The disadvantage is it's a bit hacky.

There are more details in the Clockworks manual, but here's two pictures that give you a better idea of the two choices.

PCB location for adding oscillator for using board without A²B

Oscillator with wires attached plugged in to the EVM