SBAA494A May   2021  – April 2022 PCM3120-Q1 , PCM5120-Q1 , PCM6120-Q1 , TLV320ADC3120 , TLV320ADC5120 , TLV320ADC6120

 

  1.   Trademarks
  2. 1Introduction
  3. 2Processing Blocks of TLV320ADCx120 and PCMx120-Q1
    1. 2.1 Decimation Filter Response
      1. 2.1.1 Supported Sample Rates
    2. 2.2 AGC, DRE, or DRC
      1. 2.2.1 Supported Sample Rates
      2. 2.2.2 Channel Assignment
    3. 2.3 Channel Summer, Digital Mixer, and Bi-quads
  4. 3Processing Blocks Supported for Different Sample Rates
    1. 3.1 8 kHz Sample Rate
    2. 3.2 16 kHz-48 kHz Sample Rate
    3. 3.3 96 kHz Sample Rate
    4. 3.4 192 kHz Sample Rate
    5. 3.5 384 kHz Sample Rate
    6. 3.6 768 kHz Sample Rate
  5. 4Example Configurations
  6. 5Related Documentation
  7.   A Revision History

2.3 Channel Summer, Digital Mixer, and Bi-quads

The device supports a four-channel mixer, a two channel-summer, and up to three bi-quads per channel. These features are supported for all sample rates from 8 kHz to 192 kHz. See Table 2-5 for configuration details of the summer and mixer modes. The programmable mixer feature is available only if CH_SUM[2:0] is set to 2'b00. The mixer function is only supported for input channel 1 to channel 4.

The number of bi-quad filters per channel can be set using the P0_R108:BIQUAD_CFG bit field, as shown in Table 2-6. For additional information on bi-quad filter configuration, refer to the TLV320ADCx120 and PCMx120-Q1 Programmable Biquad Filter Configuration and Applications Application Report.

Table 2-5 Channel Summing Mode and Digital Mixer Programmable Settings
P0_R107_D[3:2] : CH_SUM[1:0] CHANNEL SUMMING MODE FOR INPUT CHANNELS
00 (Default) Channel summing mode is disabled (Digital Mixer is enabled).
01 Output channel 1 = (input channel 1 + input channel 2) / 2
Output channel 2 = (input channel 1 + input channel 2) / 2
10 Reserved
11 Reserved
Table 2-6 Bi-quad Configuration Settings
P0_R108_D[6:5] : BIQUAD_CFG[1:0] BI-QUAD CONFIGURATION
00 (Default) No bi-quads per channel; bi-quads are all disabled.
01 1 bi-quad per channel
10 2 bi-quads per channel
11 3 bi-quads per channel

Table 2-7 lists the processing blocks that are available for a given input channel. These assignments are fixed and cannot be changed. The two-channel summer mode is available for the first two channels, and cannot be assigned to channels 3 and 4, even if some of the other channels are disabled. The four-channel mixer and three bi-quads per channel are available for all the channels. Input channels 1 to 2 support the most features, while channels 3 and 4 support the least number of features.

Table 2-7 Processing Block Assignments Across Input Channels
POST-PROCESSING BLOCK 1 2 3 4
Two-channel Summer √ √ x x
Four-channel Mixer √ √ √ √
Bi-quads Available 3 3 3 3