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Hello

My customer is using TAS5508C and Pre-Production stage now, and a qurious problem found.

1  They are sendng  the initial register setting at  every Power On,and no register setting done after the initial setting.

   Note: /They use auto bank -- bank1( 32,44.1,48K) bank2( 88.2, 96K), bank3( 176.4,192K)

2  change the audio source ( CD 44.1K<=>  DVD 48K) 10 times 

3  PWM output (PWM8) does not come up 1time in the source change 10times.

I had suggested them to send " ALL OF the register setting "which is relative to fs change..( They did not send PWM8 setting because they don't

use biquad for PWM8)

4  Problem seems to resolved.  They read- back  register rom TAS5508C to compare the first( inital ) setting and the when problem found-.

The register 0x96~ 0x88 are changed. ( all zero not 00 80 00 00 00 00 )

< Question >

1  Please advise what is the cause of this issue.    I think the change of 44.1K-48K is within same bank, and I believe i2c line of customer's set

 is clean ( no glitch, noise found)

2  Do you think customer should set all of the register setting at the initial setting? Especially relative to fs?

Data sheet discribes as following..

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3.5 Bank Controls
The TAS5508C permits the user to specify and assign sample-rate-dependent parameters for biquad,
loudness, DRC, and tone in one of three banks that can be manually selected or selected automatically
based on the data sampling rate. Each bank can be enabled for one or more specific sample rates via I2C
bank control register 0x40. Each bank set holds the following values:
• Coefficients for seven biquads (7 × 5 = 35 coefficients) for each of the eight channels (registers
0x51–0x88)
• Coefficients for one loudness biquad (register 0x95)
• DRC1 energy and (1 – energy) values (register 0x98)
• DRC1 attack, (1 – attack), decay, (1 – decay) values (register 0x9C)
• DRC2 energy and (1 – energy) values (register 0x9D)
• DRC2 attack, (1 – attack), decay, (1 – decay) values (register 0xA1)
• Five bass filter-set selections (register 0xDA)
• Five treble filter-set selections (register 0xDC)

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Best Regads, and hope to hearing from you soon ( within 1week)