LMX2485E EVAL National Semiconductor, LMX2485E EVAL Datasheet - Page 25

• Manufacturer Part Number: LMX2485E EVAL
• Description: BOARD EVALUATION LMX2485E
• Manufacturer: National Semiconductor
• Series: PLLatinum™r

Specifications of LMX2485E EVAL

• Main Purpose: Timing, Frequency Synthesizer
• Utilized Ic / Part: LMX2485E
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -

Complete Register Map
The complete register map shows all the functionality of all registers, including the last five.
GIS
GIS
RE
TE
R0
R1
R2 IF_
R3
R4
R5
R6 CSR[1:0]
R7
RE
TE
R0
R
R
2.1 R0 REGISTER
Note that this register has only one control bit, so the N counter value to be changed with a single write statement to the PLL.
2.1.1 RF_FN[11:0] -- Fractional Numerator for RF PLL
Refer to section 2.6.1 for a more detailed description of this control word.
2.1.2 RF_N[10:0] -- RF N Counter Value
The RF N counter contains an 8/9/12/13 and a 16/17/20/21 prescaler. The N counter value can be calculated as follows:
N = RF_P·RF_C + 4·RF_B + RF_A
RF_C
RF_B counter has an unused bit, where this extra bit is used by the delta-sigma modulator for the purposes of modulation. Consult
the tables below for valid operating ranges for each prescaler.
PD
PU
RF
_P
AT
23
23
D
0
ACCESS[3:0]
≥
Max{RF_A, RF_B} , for N-2
RF
_P
22
22
0
0
21
21
1
0
RF_CPF[3:0]
20
20
0
0
RF_FD[21:12]
RF_R[5:0]
19
19
DATA[19:0] ( Except for the RF_N Register, which is [22:0] )
0
0
RF_N[10:0]
RF_N[10:0]
RF_CPG[3:0]
18
18
0
0
17
17
FM
0
DITH
[1:0]
-1 ... N+2
16
16
0
15
15
0
FM
[1:0]
FM
is a necessary condition. This rule is slightly modified in the case where the
14
14
0
IF_N[18:0]
DIV
13
13
0
4
DATA[22:0]
_2X
OS
12
12
25
C
0
RF_TOC[13:0]
OS
_O
UT
11
11
C
1
RF_FD[11:0]
IF_R[11:0]
IF_
CP
10
10
P
0
RF_FN[21:12]
RF
CP
P
9
_
0
9
IF_
P
8
1
8
RF_FN[11:0]
RF_FN[11:0]
IF_
RS
7
T
7
RF
_R
ST
6
6
MUX
[3:0]
IF_
CP
T
5
5
RF
_C
PT
4
4
C3
3
0
0
0
1
1
1
1
3
C2
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2
0
1
1
0
0
1
1
2
C1
1
1
0
1
0
1
0
1
1
C0
C0
0
0
1
1
1
1
1
1
1
0
0