STA339BW datasheet(60/78 Pages) STMICROELECTRONICS

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STA339BW

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DocID15251 Rev 8

For example, in case of different input sources (different sampling rates), the three different

sets of coefficients can be downloaded once at the start up, and during the normal play it is

possible to switch among the three RAM blocks allowing a faster operation, without any

additional download from the microcontroller.

To write the coefficients in a particular RAM bank, this bank must be selected first writing

bit 0 and bit 1 in register 0x31. Then the write procedure below can be used.

Note that as soon as a RAM bank is selected, the EQ settings are automatically switched to

the coefficients stored in the active RAM block.

Note:

The read write operation on RAM coefficients works only if RLCKI (pin29) is switching and

stable (ref. Table 9, tLRJT timing) and PLL must be locked (ref bit D7 reg 0x2D).

Reading a coefficient from RAM

Select the RAM block with register 0x31 bit1, bit0.

Write 6 bits of address to I2C register 0x16.

Write 1 to R1 bit in I2C address 0x26.

Read top 8 bits of coefficient in I2C address 0x17.

Read middle 8 bits of coefficient in I2C address 0x18.

Read bottom 8 bits of coefficient in I2C address 0x19.

Reading a set of coefficients from RAM

Select the RAM block with register 0x31 bit1, bit0.

Write 6 bits of address to I2C register 0x16.

Write 1 to RA bit in I2C address 0x26.

Read top 8 bits of coefficient in I2C address 0x17.

Read middle 8 bits of coefficient in I2C address 0x18.

Read bottom 8 bits of coefficient in I2C address 0x19.

Read top 8 bits of coefficient b2 in I2C address 0x1A.

Read middle 8 bits of coefficient b2 in I2C address 0x1B.

Read bottom 8 bits of coefficient b2 in I2C address 0x1C.

10. Read top 8 bits of coefficient a1 in I2C address 0x1D.

11. Read middle 8 bits of coefficient a1 in I2C address 0x1E.

12. Read bottom 8 bits of coefficient a1 in I2C address 0x1F.

13. Read top 8 bits of coefficient a2 in I2C address 0x20.

14. Read middle 8 bits of coefficient a2 in I2C address 0x21.

15. Read bottom 8 bits of coefficient a2 in I2C address 0x22.

16. Read top 8 bits of coefficient b0 in I2C address 0x23.

17. Read middle 8 bits of coefficient b0 in I2C address 0x24.

18. Read bottom 8 bits of coefficient b0 in I2C address 0x25.

STA339BW Datasheet(PDF) 60 Page - STMicroelectronics