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=== Fix for low frequency's ===
=== Fix for low frequency's ===
if frequency < 45000
*if frequency < 45000
* set tuner registry 1 to 0x06
** set tuner registry 1 to 0x06
* set tuner registry 2 to 0x11
** set tuner registry 2 to 0x11


=== Fix clock out ===
=== Fix clock out ===

Revision as of 19:44, 6 December 2009

Tuner used together with AF9035. http://www.fitipower.com.tw/main.htm?pid=9&ID=57

Specifications

Don't trust this blindly. Division is always integer division.

Tuner general info

I2C address is 0xC0. There are 18 8bit large tuner registers indexed from 0.

Index Name
1 FA
2 FP
3,4 XIN
5 VCO
6 VCO_SELECT
14 VCO_CALIBRATE

Init/Reset

Enable tuner:

  • write 1 to GPIO 0xD8EB
  • write 1 to GPIO 0xD8EC
  • write 1 to GPIO 0xD8ED

Enable led:

  • write 1 to GPIO 0xD8D1
  • write 1 to GPIO 0xD8D0

UnInit

Disable led:

  • write 0 to GPIO 0xD8D1
  • write 0 to GPIO 0xD8D0

Tune

Tuning is based on 2 parameters:

  • bandwidth in Hz, can be 6000,7000 or 8000
  • frequency in Hz, can be the regular DVB-T frequency's

Init tuning

  • write 0x0F to tuner register 7
  • write 0x3E to tuner register 8
  • write 0xB8 to tuner register 10
  • write 0x80 to tuner register 11
  • write 0x04 to tuner register 13

Generate the frequency of VCO and the VCO divider

fvco is a parameter

  • if frequency < 54000
    • set fvco to frequency * 64
    • set tuner registry 5 to 0x82
  • if 54000 =< frequency < 108000
    • set fvco to frequency * 32
    • set tuner registry 5 to 0x42
  • if 108000=< frequency < 216000
    • set fvco to frequency * 16
    • set tuner registry 5 to 0x22
  • if 216000=< frequency < 432000
    • set fvco to frequency * 8
    • set tuner registry 5 to 0x12
  • if frequency > 432000
    • set fvco to frequency * 4
    • set tuner registry 5 to 0x0A

Calculate XIN

fraction is a 16bit unsigned parameter, xin is a parameter, fvco is a pre-calculated parameter, xdiv is a parameter

  • set xdiv equal to fvco / 18000
  • set fraction equal to fvco minus xdiv multiplied by 18000
  • set fraction equal to fraction left shifted 15 times and then divided by 18000
  • if fraction is greater or equal to 16384
    • set fractional equal to fractional plus 32768
  • if fraction is equal to 0
    • set xin equal to 0
  • if 0 < fraction < 511
    • set xin equal to 0x200
  • if 511 < fraction <= 65025
    • set xin equal to fraction
  • if 65025 < fraction
    • set xin equal to 0xfe00
  • write xin right shifted 8 times to tuner register 3
  • write xin only 8 low bits to tuner register 4

Calculate FP and FA

fvco is a pre-calculated parameter, xdiv is a pre-calculated parameter, xdivr is a parameter, fp is a 8 bit wide parameter, fa is a parameter

  • set xdivr equal to xdiv
  • if fvco minus xdiv multiplied by 18000 is greater equal to 9000
    • set xdivr equal to xdiv + 1
  • set fp equal to xdivr / 8
  • set fa equal to xdivr minus fp left shifted 3 times
  • if fa is less then 2
    • set fp equal fp minus 1
    • set fa equal fa plus 8
  • write fa to tuner register 1
  • write fp to tuner register 2

Select bandwidth

  • if bandwidth = 8000
    • set tuner registry 6 to 0x0
  • if bandwidth = 7000
    • set tuner registry 6 to 0x40
  • if bandwidth = 6000
    • set tuner registry 6 to 0x80

Pre VCO selection

fvco is a pre-calculated parameter, vco_sel is a parameter

  • if fvco < 2320000
    • set vco_sel equal to 0
    • set tuner registry 6 equal to tuner registry 6 bitwise anded with the bitwise complement of 0x18
  • if 2320000 <= fvco < 3080000
    • set vco_sel equal to 1
    • set tuner registry 6 equal to tuner registry 6 bitwise or'ed with 0x10
  • if 3080000 <= fvco
    • set vco_sel equal to 1
    • set tuner registry 6 equal to tuner registry 6 bitwise or'ed with 0x08

Fix for low frequency's

  • if frequency < 45000
    • set tuner registry 1 to 0x06
    • set tuner registry 2 to 0x11

Fix clock out

  • set tuner registry 6 to the result of a bitwise OR between tuner registry 6 and 0x20

Write frequency parameters

  • write tuner registry 0-6