SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
The data filter output can be represented in either 32-bit or 16-bit format.
32-bit data filter representation:
16-bit data filter representation:
For example, for the data filter configuration below:
The data filter with a 25-bit signed output value can be in the range of –2,097,152 to 2,097,152. But, 16-bit signed output supports values only from –32,768 to 32,767. Therefore, it is required to configure shift control bits (SDDPARMx.SH) to 7 to represent the data filter output correctly in 16-bit format. Table 13-4 shows the configuration settings of shift control bits for different OSR and filter types.
OSR | Sinc1 | Sinc2 | SincFast | Sinc3 |
---|---|---|---|---|
1 to 31 | 0 | 0 | 0 | 0 |
32 to 40 | 0 | 0 | 0 | 1 |
41 to 50 | 0 | 0 | 0 | 2 |
51 to 63 | 0 | 0 | 0 | 3 |
64 to 80 | 0 | 0 | 0 | 4 |
81 to 101 | 0 | 0 | 0 | 5 |
102 to 127 | 0 | 0 | 0 | 6 |
128 to 161 | 0 | 0 | 1 | 7 |
162 to 181 | 0 | 0 | 1 | 8 |
182 to 203 | 0 | 1 | 2 | 8 |
204 to 255 | 0 | 1 | 2 | 9 |
256 | 0 | 2 | 3 | 9 |