ZL50022
Data Sheet
External Read/Write Address: 0042H
Reset Value: 16B1H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
CFN
15
CFN
14
CFN
13
CFN
12
CFN
11
CFN
10
CFN
9
CFN
8
CFN
7
CFN
6
CFN
5
CFN
4
CFN
3
CFN
2
CFN
1
CFN
0
Bit
Name
Description
15 - 0
CFN15 - 0 Center Frequency Number (CFN) Lower 16 Bits: The total binary value of these bits
and the CFRU register bits defines the output center frequency number according to the
following formula:
CFN
-----------
fOUT =
× fMCLK
226
where, fOUT is desired output center frequency, while fMCLK is frequency of DPLL master
clock. For given master clock frequency of 100 MHz, and desired output center fre-
quency of 65.536 MHz, the CFN has the value of:
26
26
65.536MHz
-------------------------------
CFN = 2
×
= 2 × 0.65536 = 43980465 = 29F16B1H
100MHz
The register contents should be changed only if compensation for input oscillator (or
crystal) frequency offset is required.
e.g., if master clock frequency is off by +20 ppm (100.002 MHz -> 5 times multiplied c20i
of 20.0004 MHz), the CFN should be programmed to be:
26
26
65.536MHz
----------------------------------
CFN = 2
×
= 2 × 0.65534689 = 43979585 = 29F1341H
100.002MHz
The default value of this register SHOULD NOT be changed in any other circumstances.
Table 30 - Centre Frequency Register - Lower 16 Bits (CFRL)
External Read/Write Address: 0043H
Reset Value: 029FH
15
0
14
0
13
0
12
0
11
0
10
0
9
8
7
6
5
4
3
2
1
0
CFN
25
CFN
24
CFN
23
CFN
22
CFN
21
CFN
20
CFN
19
CFN
18
CFN
17
CFN
16
Bit
Name
Description
Reserved. In normal functional mode, these bits MUST be set to zero.
15 - 10
9 - 0
Unused
CFN25 - 16 Center Frequency Number (CFN) Upper 10 Bits: The total binary value of these bits
and the CFRL register bits represents the center frequency number (CFN) explained
under CFRL register bits explanation.
The default value of this register should be changed only if compensation for input oscil-
lator (or crystal) frequency offset is required, and SHOULD NOT be changed in any other
circumstances.
Table 31 - Centre Frequency Register - Upper 10 Bits (CFRU)
66
Zarlink Semiconductor Inc.
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
