Service Manual

PROGRAMMING
3-3
Part No. 001-3474-002
NM1 and NM2 are calculated as follows:
N = (NM1 + 2) x 64 + NM2 x 65 Where: N = total division ratio
NM1 = Number of main divider cycles when prescaler modulus equals 64
NM2 = Number of main divider cycles when prescaler modulus equals 65
Example:
Calculate NM1 and NM2 to Receive 454.500 MHz.
LO = 454.5 + 52.95 = 507.45 MHz
(52.95 MHz IF with High Side Injection)
N = RX LO ÷ FCM = 507.45 ÷ 0.05 = 10149
(FMC = Loop Reference Frequency)
NM2 = 64 x FRAC [N ÷ 64]
= 64 x FRAC [10149 ÷ 64]
= 64 x 0.57813
= 37
NM1 = INTEGER [N ÷ 64] - 2 - NM2
= 158 - 2 - 37
= 119
Figure 3-1 D-WORD