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CHAPTER 13 PLL FREQUENCY SYNTHESIZER
User’s Manual U15104EJ2V0UD
Data is set to the PLL data registers (PLLR and PLLR0) as follows.
After setting the above PLL data registers (PLLR and PLLR0), data must be transferred to the
programmable counter by setting bit 0 (PLLNS0) of the PLL data transfer register (PLLNS).
(2) Pulse swallow mode (HF)
(a) Calculating division value N (value set to PLL data register)
N =
f
VCOL
f
r
where,
f
VCOL
: Input frequency of V
COL
pin
f
r
:
Reference frequency
(b) Example of setting PLL data register
An example of setting the PLL data register to receive broadcasting stations in the following SW band
is shown below.
Receive frequency:
25.50 MHz (SW band)
Reference frequency:
10 kHz
Intermediate frequency: 450 kHz
Division value N is calculated as follows:
N =
f
VCOL
=
25500 + 450
= 2595 (decimal)
f
r
10
= 0A23H (hexadecimal)
PLLR
Programmable counter value
Don’t care
Fixed to 0
PLLRL
PLLRH
b7
b16
b6
b15
b5
b14
b4
b13
b3
b12
b2
b11
b1
b10
b0
b9
b7
b8
b6
b7
b5
b6
b4
b5
0
0
0
0
D
0
0
1
1
0
1
0
0
0
0
b3
b4
b2
b3
b1
b2
b0
b1
b7
b0
b6 b5 b4 b3 b2 b1 b0
PLLR0
PLLSCN
Содержание mPD178053
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