STA369BW Datasheet, PDF (66/88 Pages) STMicroelectronics – Sound Terminal® 2.1-channel high-efficiency digital audio system

Register description
STA369BW
Writing a single coefficient to RAM
1. Select the RAM block with register 0x31 bit1, bit0.
2. Write 6 bits of address to I²C register 0x16.
3. Write top 8 bits of coefficient in I²C address 0x17.
4. Write middle 8 bits of coefficient in I²C address 0x18.
5. Write bottom 8 bits of coefficient in I²C address 0x19.
6. Write 1 to W1 bit in I²C address 0x26.
Writing a set of coefficients to RAM
1. Select the RAM block with register 0x31 bit1, bit0.
2. Write 6 bits of starting address to I²C register 0x16.
3. Write top 8 bits of coefficient b1 in I²C address 0x17.
4. Write middle 8 bits of coefficient b1 in I²C address 0x18.
5. Write bottom 8 bits of coefficient b1 in I²C address 0x19.
6. Write top 8 bits of coefficient b2 in I²C address 0x1A.
7. Write middle 8 bits of coefficient b2 in I²C address 0x1B.
8. Write bottom 8 bits of coefficient b2 in I²C address 0x1C.
9. Write top 8 bits of coefficient a1 in I²C address 0x1D.
10. Write middle 8 bits of coefficient a1 in I²C address 0x1E.
11. Write bottom 8 bits of coefficient a1 in I²C address 0x1F.
12. Write top 8 bits of coefficient a2 in I²C address 0x20.
13. Write middle 8 bits of coefficient a2 in I²C address 0x21.
14. Write bottom 8 bits of coefficient a2 in I²C address 0x22.
15. Write top 8 bits of coefficient b0 in I²C address 0x23.
16. Write middle 8 bits of coefficient b0 in I²C address 0x24.
17. Write bottom 8 bits of coefficient b0 in I²C address 0x25.
18. Write 1 to WA bit in I²C address 0x26.
The mechanism for writing a set of coefficients to RAM provides a method of updating the
five coefficients corresponding to a given biquad (filter) simultaneously to avoid possible
unpleasant acoustic side effects. When using this technique, the 6-bit address specifies the
address of the biquad b1 coefficient (for example, 0, 5, 10, 20, 35 decimal), and the
STA369BW generates the RAM addresses as offsets from this base value to write the
complete set of coefficient data.
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Doc ID 022033 Rev 1