User's Manual

Bluegiga Technologies Oy
Page 35 of 52
14.2.6 PCM Configuration
Configure the PCM by using PSKEY_PCM_CONFIG32 and PSKEY_PCM_LOW_JITTER_CONFIG, see your
PS Key file. The default for PSKEY_PCM_CONFIG32 is 0x00800000, i.e. first slot following sync is active, 13-
bit linear voice format, long frame sync and interface master generating 256kHz PCM_CLK from 4MHz
internal clock with no tri-state of PCM_OUT.
14.3 Digital Audio Interface (I
2
S)
The digital audio interface supports the industry standard formats for I²S, left-justified or right-justified. The
interface shares the same pins as the PCM interface, which means each audio bus is mutually exclusive in its
usage. Table 17 lists these alternative functions.
PCM Interface
I
2
S Interface
PCM_OUT SD_OUT
PCM_IN SD_IN
PCM_SYNC WS
PCM_CLK SCK
Table 18: Alternative Function of the Digital Audio Bus Interface on the PCM Interface
Configure the digital audio interface using PSKEY_DIGITAL_AUDIO_CONFIG. Table 18 describes the values
for the PS Key (PSKEY_DIGITAL_AUDIO_CONFIG) that is used to set-up the digital audio interface. For
example, to configure an I
2
S interface with 16-bit SD data set PSKEY_DIGITAL_CONFIG to 0x0406.