MC72000 Freescale Semiconductor, MC72000 Datasheet - Page 39

• Manufacturer Part Number: MC72000
• Description: Integrated Bluetooth Radio
• Manufacturer: Freescale Semiconductor

LUT R
The following table lists all values of RxCx for supported reference.
6.4.4 M-Dual Port Multiplier and B-Dual Port Multiplier
For proper operation of the dual-port synthesizer, it is necessary to maintain a constant deviation injection
at the input of Port 2 of the VCO. As appears from the Transmit ROM operation and Figure 17, the output
of the LUT is fed to a digital multiplier prior to being presented to the input of the modulation DAC. Since
the LUT values decrease proportionately with input reference frequency, the multiplier must scale these
values to achieve a constant deviation. This scaling is linear. Two programmable constants are used to
form the equation of a line, the M & B dual-port multipliers. M-Dual Port Digital Multiplier Value (R17/
15-8), determines the slope, and B-Dual Port Digital Multiplier Value (R8/7-0), determines the intercept.
M-Dual Port Digital Multiplier = (f
B-Dual Port Digital Multiplier = (f
Table 20 contains slope and intercept point values across all supported input reference frequencies.
6.4.5 Dual-Port Programmable Delay (R7/15-11)
It is necessary to maintain a constant deviation at Port2 of the VCO. Likewise, it is necessary to maintain a
constant phase at the FV and FR inputs of the main charge pump. The total delay from the output of the
LUT to the FV input of the charge pump is given as follows:
LUT → FV delay = 10.5 / (f
Likewise, the total delay from the LUT to the FR input of the charge pump is as follows:
LUT → FR delay = 28 ns + Delay
where delay is the programmed delay value shown in Table 19. Therefore, for a given external reference
frequency:
Delay = 10.5 / (f
MOTOROLA
4
C
2b2
= INT((415.2+2)/4)
ref
External) - 28 ns.
Freescale Semiconductor, Inc.
ref
For More Information On This Product,
MC72000 Advance Information Data Sheet
External)
b10
ref
ref
R1C1
R2C2
R2C3
R2C4
R3C1
R3C2
R3C3
R3C4
R4C2
R4C3
R4C4
External) /13 MHz * 97
= INT(104.3)
External) /13 MHz * 108
Table 18. RxCx Constants
Go to: www.freescale.com
Preliminary
b10
0.9999739537
0.9980246857
0.9911665663
0.9678427310
0.1881990082
0.5249014674
0.7660791186
0.9043672052
0.5229292198
0.7572459756
0.8722099597
= 104
10
b10
10
or 011010000
Radio Functional Description
b2
or 68
b16
39