The OUTSUM block allows addition of samples from each DUC in the multi-DUC. It is also possible to add the output samples from the adjacent multi-DUC. Field OUTSUM_SEL in register OUTSUM (8.5.22) controls the summation for each multi-DUC. The functionality of the block can be represented by the following equation:
In order to avoid overflow, rounding operation is performed after the addition to reduce the word size back to 16-bits. Exact number of bits rounded depends on the number of channels added. Table 44 shows the description of round after the summation.
|# OF CHANNELS ADDED||# OF BITS ROUNDED|
|0||0, Use bits[15:0] from the result|
|1||Use bits[16:1] from the result and bit used for rounding|
|2||Use bits[17:2] from the result and bits[1:0] used for rounding|
|3||Use bits[18:3] from the result and bit[2:0 used for rounding|
|4||Use bits[19:4] from the result and bit[3:0] used for rounding|