1.2.6 CORCON Register Usage

Many functions of the DSP Library place the device into a special operating mode by modifying the CORCON register. On the entry of these functions, the CORCON register is pushed to the stack. It is then modified to correctly perform the desired operation, and lastly, the CORCON register is popped from the stack to preserve its original value. This mechanism allows the library to execute without disrupting the CORCON setting.

The CORCON register is configured to place the target device into the following operational mode.

• DSP multipliers are configured to utilize signed fractional data.
• Accumulator saturation is enabled for Accumulator A and Accumulator B.
• Saturation mode is set to 9.63 saturation (Super saturation).
• Data Space Write saturation is enabled.
• Convergent (unbiased) rounding is enabled.

For a detailed explanation of the CORCON register and its effects, refer to the respective device data sheets.