SM5166AV

NIPPON PRECISION CIRCUITS—7

Reference counter frequency divider setting

Input data example

frequency is 12.8 MHz and the channel bandwidth

the reference frequency divider ratio R is given by:

Therefore, the reference counter count is 192

figure 5.

Figure 3. Swallow counter and main counter frequency divider data example

Input

Data

12

345

678

9

10 11 12 13 14 15 16 17

MSB

LSB

22

222

222

22

222

222

10

9

876

543

21

043

210

Main counter

(11-bit : 32 to 2047)

Swallow counter

(5-bit : 0 to 31)

Latch selection bit : Set to "0"

00

100

111

01

000

100

0

Figure 4. Reference counter data and LD output setting format

DATA

12

345

678

9

10

11 12 13

14 15 16

17

MSB

LSB

22

222

222

22

222

12

11

10

98

765

43

210

(Reference counter 13-bit : 5 to 8191)

Latch selection bit : Set to "1"

Test bits : (15, 16) = (0, 0) for normal operation

LD output setting bit∗

LOW-level output when 0.

NR

Xtal

f

CH

-----------

Xtal

f

R

3

×

---------------

12.8

0.025 3

⁄

--------------------

1536

8

192

×

==

=

=

=