JAJSKH5A April 2022 – May 2024 TUSB1142
PRODUCTION DATA
Fast Adaptive EQ will distinguish between a short and long channel and select a pre-determined EQ setting based on which channel is detected. Fast AEQ is available only I2C mode. Fast AEQ is enabled when AEQ_MODE = 0 and AEQ_EN = 1.
The EQ setting used for short channel should be programmed into CEQ1_SEL and CEQ2_SEL registers. It is recommended to program these registers about 1 dB to 2 dB more than the loss of post channel (XCD). For example, if post channel is 0.5 inches, then assuming -1dB insertion loss per inch at 5 GHz, CEQ1_SEL and CEQ2_SEL should be programmed to 1.5 to 2.5 dB. It is recommended to perform USB 3.2 Rx JTOL Short channel test to find the optimal short channel setting.
The EQ setting used for long channel should be programmed into LONG_CEQ1 and LONG_CEQ2. It is recommended to program these registers about 4 to 5 dB more than the loss of post channel (XCD). For example, if post channel is 0.5 inches, then assuming -1 dB per inch at 5 GHz, LONG_CEQ1 and LONG_CEQ2 should be programmed to 4.5 to 5.5 dB. It is recommended to perform USB 3.2 Rx JTOL Long channel test to find the optimal long channel setting.