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Clock modulation parameter register (cmpr), Modulation parameter register contents – FUJITSU MB91460 SERIES FR60 User Manual

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Chapter 17 Clock Modulator

2.Clock Modulator Registers

Clock Modulation Parameter Register (CMPR)

The Modulation Parameter Register (CMPR) determines the modulation degree in frequency modulation
mode.

Figure 2-3 Modulation parameter register

The modulation parameter determines the degree of modulation and the maximal and minimal occurring

frequencies in the modulated clock. Please refer to the application note for a description of an approach to

select the optimal setting.

Each set of possible modulation parameters refers to a particular PLL frequency. The PLL frequency and the

selected parameter must match. Please refer to the following table of possible settings.

The modulation parameter affects only the frequency modulation mode.

Note:

The modulation parameter must be changed only when the modulator is disabled and the RUN flag is 0

(FMOD=0, FMODRUN=0).

Modulation parameter register contents

modulator enabled in frequency modulation mode,
modulator is calibrating, modulation not active

1

1

0

modulator is running in frequency modulation mode
modulation is active

1

1

1

others not allowed

Table 2-3 Function of each bit of the modulation parameter register (CMPR)

Bit name

Function

bit 15, 14

Undefined

Table 2-2 States of the modulator

FMOD

PDX

FMODRUN

(read only)

Initial value

1 1 1 1 1 1 0 1

B

R/W R/W R/W R/W

R/W

R/W

R/W R/W

Address:

0004B9H

CMPRL (lower)

Initial value

X X 0 0 0 0 0 1 0

B

CMPRH (upper)

0004B8H

15

14

13

12

11

10

9

8

1

0

3

2

5

4

7

6

R/W R/W

R/W

R/W

R/W R/W

R/W

: Readable and writable

Undefined value

X

:
: Undefined