STA309A datasheet(59/67 Pages) STMICROELECTRONICS

59 / 67 page

STA309A

Registers

Doc ID 13855 Rev 4

59/67

7.6

Writing a set of coefficients to RAM

write top 2-bits of starting address to I2C register 0x3B

write bottom 8-bits of starting address to I2C register 0x3C

write top 8-bits of coefficient b1 in I2C address 0x3D

write middle 8-bits of coefficient b1 in I2C address 0x3E

write bottom 8-bits of coefficient b1 in I2C address 0x3F

write top 8-bits of coefficient b2 in I2C address 0x40

write middle 8-bits of coefficient b2 in I2C address 0x41

write bottom 8-bits of coefficient b2 in I2C address 0x42

write top 8-bits of coefficient a1 in I2C address 0x43

10. write middle 8-bits of coefficient a1 in I2C address 0x44

11. write bottom 8-bits of coefficient a1 in I2C address 0x45

12. write top 8-bits of coefficient a2 in I2C address 0x46

13. write middle 8-bits of coefficient a2 in I2C address 0x47

14. write bottom 8-bits of coefficient a2 in I2C address 0x48

15. write top 8-bits of coefficient b0 in I2C address 0x49

16. write middle 8-bits of coefficient b0 in I2C address 0x4A

17. write bottom 8-bits of coefficient b0 in I2C address 0x4B

18. write 1 to WA bit in I2C address 0x4C

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 10-bit address would specify the address of the biquad b1

coefficient (for example, decimals 0, 5, 10, 15, …, 100, … 395), and the STA309A will

generate the RAM addresses as offsets from this base value to write the complete set of

coefficient data.

STA309A Datasheet(PDF) 59 Page - STMicroelectronics