Fitipower

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