MC44S803EP FREESCALE [Freescale Semiconductor, Inc], MC44S803EP Datasheet - Page 14

• Manufacturer Part Number: MC44S803EP
• Description: Low Power CMOS Broadband Tuner
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

PROGRAMMABLE R1 & R2 REFERENCE DIVIDERS
REGISTER (CR-2)
which are divided down from the crystal frequency by the
divide ratios specified by the respective Divider Ratio bits.
The Ref Buf En bit enables the reference buffers for LO1 and
REFERENCE BUFFER REGISTER (CR-3)
oscillator signal. The oscillator frequency can be changed by
the R3 divider before it exits the BufIO pins. The R3 divider
MC44S803
14
MSB
MSB
Osc Sel
R15
R14
Reserved
MSB
R
1
0
Selects the First and Second LO reference frequencies,
The BufIOP and BufIOM pins output a buffered reference
R9
0
R14
R13
R
R1 Divide Ratio
1
0
R8
0
Reserved
R12
0
R13
R
1
R7
R11
0
0
R12
R
1
R10
1
R6
1
R11
Reserved
R
1
Ref
Buf
R9
En
1
Table 14. Oscillator Sel Bit
R10
R
1
R5
0
Figure 9. Reference Oscillator Register Format
R8
0
Figure 10. Reference Divider Register Format
R9
R
1
Ref Osc
R4
R7
4.0 MHz to <16 MHz
0
Crystal Frequency
0
16 MHz to 28 MHz
Figure 11. Reference Buffer Register
Buf
I/O
R8
0
R6
0
Gain
Buf
R3
R7
0
0
R5
R2 Divide Ratio
0
State
R6
Tri
1
Sine Wave Buffer Output
R2
0
R4
0
Osc
Scr
R5
0
LO2. In normal operation, this bit is programmed to 1. The
Reference Dividers are actually R+1 dividers, therefore the
number to program into this register for R1 Divide Ratio and
R2 Divide Ratio must be one less than the desired divide
ratio.
does not effect which frequency the tuner is tuned to. In
addition, the gain of the sine wave buffer can be selected. If
Buf Gain bit is 1 then the buffer is at full gain, if it is 0 it is at
half gain.
R3
R1
1
Mux
0
R4
0
4
R2
Mux
0
R3
0
3
R0
0
Osc Sel
R1
0
R2
R3 Divide Ratio
0
0
1
A3
0
R0
0
R1
0
Address Bits
A3
R0
0
A2
0
0
Address Bits
A2
A3
0
0
Freescale Semiconductor
A1
0
Address Bits
A1
A2
1
0
LSB
A0
1
LSB
A1
A0
1
0
LSB
A0
1
Reset
Reset
State
State
Reset
State