7.7.5.12.1 Bridging With Rate Conversion

When a peripheral-to-peripheral audio transfer must be performed and the input (receive) rate differs from the output (transmit) rate, one or more DSPs must be enabled to perform the rate conversion.

When the input and output rates are the same (44.1 Ksps, for example) but the audio clock sources are not generated from the same clock sources (two different crystal oscillators may have the same typical clock frequency but differ by some ppm, for example), one or more DSPs must be also enabled.

Direct access prevent usage of system memory. Direct Access mode must be configured at the input and at the output in ASRC_MR.DATHRx and ASRC_MR.DARHRx and related peripherals must be selected via ASRC_DAPSELR.IN_CHx and ASRC_DAPSELR.OUT_CHx (see the following figure).