How do you program the CXA3250AN TV Tuner PLL chip?

On a previous topic I was instructed to make a new topic regarding how to program it, not that I'm having issues. I have both the datasheet and the I2C communications up and running with the chip, I just can't decipher what I need to send and how to get a result. My goal is to feed in some numbers (of which I have no idea and need help understanding) and have it shoot out a frequency say 101.1 MHz at the IF. The problem is, I don't understand the protocol in the datasheet and need help understanding what to send and how to get the numbers. Are there any tuner specialists out there that can help me?

Page 21 is transmit info

The IF frequency seems to be designed for 45 MHz. Perhaps it is not possible to use an IF of 101.1 MHz.

johnwasser:
The IF frequency seems to be designed for 45 MHz. Perhaps it is not possible to use an IF of 101.1 MHz.

I don't want the IF 101.1 MHz, I want the chip code to tune it to 101.1 and have it output at 45.

Looks like when you use I2C you send 5 bytes:

Address: 1 1 0 0 0 MA1 MA0 0
Divider Byte 1: 0 M9 M8 M7 M6 M5 M4 M3
Divider Byte 2: M2 M1 M0 S4 S3 S2 S1 S0
Control byte: 1 CP 0 CD x R1 R0 OS
Band Switch byte: x x x x BS4 BS3 BS2 BS1

MA0-1: address setting
M0-9: main divider frequency division ratio setting
S0-4: swallow counter frequency division ratio setting
CD: charge pump OFF (when “1”)
OS: varicap output OFF (when “1”)
CP: charge pump current switching (200 ?A when “1”, 50 ?A when “0”)
BS1-4: band switch control (output PNP transistor ON when “1”)
R0-1: reference divider frequency division ratio setting.
See the Reference Divider Frequency Division Ratio Table.

You want the Local Oscillator Frequency (Fosc) to be 45 MHz below the desired tuning frequency. To tune to 101.1 MHz you want the Fosc to be 56.1 MHz.

Fosc = Fref * (32*M+S)

The Fref is derived from the reference crystal (4 MHz?) and the reference divider set by R0 and R1:

R1, R0
0, 1: Divide by 128 = 31.25 kHz
1, 1: Divide by 64 = 62.5 kHz
X, 0: Divide by 80 = 50 kHz (0.05 MHz)

If you use divide-by-80:

56.1 = 0.05 * (32M+S)
1122 = 32
M + S
M = 35 (integer part of 1122/32)
S = 2 ((fractional part of 1122/32) * 32)