Wednesday, July 8, 2015

HAP-Z1ES PCM1795 Register Settings

I measured the serial configuration interface of the PCM1795.  The following register settings were found in the DSD mode (for both DSD source and DSD remastering).  DMF[1:0] = Reg18[4:3] = 01, so DSD Filter-2 is used for the analog FIR.  In addition to the on-chip FIR filtering, there is additional first-order FIR filtering (1+z^{-1}) realized by connecting two current outputs together with one input delayed by one sample.  

Reg16 = 0xff
Reg17 = 0xff
Reg18 = 0x54
Reg19 = 0x00
Reg20 = 0x20
Reg21 = 0x00
Reg22 = 0x00
Reg23 = 0x00