Operating instructions

5-10 Controller Board
2.10.2 Transmit Audio
Transmit audio can be sourced from either internal or external microphone path. Both the internal and
external microphone carries a 5V bias through a resistor to MAKO MIC_BIAS pin. The MAKO,
through SPI, selects the appropriate microphone path to route to the necessary gain stages and
converter that will send 16-bit PCM audio to the OMAP for signal processing via the SSI bus.
The transmit gain stages in the MAKO is calibrated based on an 8mV input under standard test
conditions. The microphone sensitivity is programmable through the use of CPS.