sta381bw STMicroelectronics, sta381bw Datasheet - Page 137

• Manufacturer Part Number: sta381bw
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

STA381BW
Writing a set of coefficients to RAM
1.
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10. Write bottom 8 bits of coefficient a1 in I
11. Write top 8 bits of coefficient a2 in I
12. Write middle 8 bits of coefficient a2 in I
13. Write bottom 8 bits of coefficient a2 in I
14. Write top 8 bits of coefficient b0 in I
15. Write middle 8 bits of coefficient b0 in I
16. Write bottom 8 bits of coefficient b0 in I
17. Write 1 to WA bit in I
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
STA381BW generates the RAM addresses as offsets from this base value to write the
complete set of coefficient data.
Write 6 bits of starting address to I
Write top 8 bits of coefficient b1 in I
Write middle 8 bits of coefficient b1 in I
Write bottom 8 bits of coefficient b1 in I
Write top 8 bits of coefficient b2 in I
Write middle 8 bits of coefficient b2 in I
Write bottom 8 bits of coefficient b2 in I
Write top 8 bits of coefficient a1 in I
Write middle 8 bits of coefficient a1 in I
2
C address 0x26.
Doc ID 018835 Rev 2
Register description: Sound Terminal compatibility
2
2
2
2
2
2
C register 0x16.
C address 0x17.
C address 0x1A.
C address 0x1D.
C address 0x20.
C address 0x23.
2
2
2
2
2
2
2
2
2
2
C address 0x18.
C address 0x1B.
C address 0x1E.
C address 0x21.
C address 0x24.
C address 0x19.
C address 0x1C.
C address 0x1F.
C address 0x22.
C address 0x25.
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