Sundance SMT702 - Manual (Page 44)

4.3.1.2.19 Frequency Synthesizer (LMX2531) Register R1 – 0xC4
(write and read).
Offset 0x0400 - Frequency Synthesizer (LMX2531) Register R1 – 0xC4 (write and read)
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
2 Reserved Reserved ICP[4]
Default ‘000000’ ‘1’ ‘0’
1 ICP[3:0] N[10:8] NUM[21:20]
Default ‘000’ ‘000’ ‘00’
0 NUM[19:12]
Default ‘00000000’
Offset 0x0400 - Frequency Synthesizer (LMX2531) Register R1 – 0xC4 (write and read)
Setting Bit 9-0 Fractional numerator (NUM[21:12])
0 0 Value between 0 (all 0s) and 4194303 (all 1s)
Setting Bit 12-10 N Counter (N[10:8])
0 0 Value between 0 (0x37) and 2039 (0x3F7)
Setting Bit 16-13 Charge Pump Current (ICP[4:0])
0 0 0x0 corresponds to 90uA (state 1x) and 0xF (State 16x) to 1440uA (90uA per state)
4.3.1.2.20 Frequency Synthesizer (LMX2531) Register R2 – 0xC8
(write and read).
Offset 0x0400 - Frequency Synthesizer (LMX2531) Register R2 – 0xC8 (write and read)
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
2 Reserved Reserved DEN[11:0]
Default ‘00000’ ‘1’ ‘00’
1 DEN[11:0]
Default ‘00000000’
0 DEN[11:0] R[5:0]
Default ‘00’ ‘000000’
Offset 0x0400 - Frequency Synthesizer (LMX2531) Register R2 – 0xC8 (write and read)
Setting Bit 5-0 R Counter Value (R[5:0])
0 0 R Country Value – These bits determine the phase detector frequency. Only possible
values are 1, 2, 4, 8, 16 or 32
Setting Bit 17-6 Fractional Denominator DEN[11:0]
0 0 Value between 0 (all 0s) and 4194303 (all 1s)