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

Page 260

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Chapter 17 Clock Modulator

2.Clock Modulator Registers

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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

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