5 calculating the frequency – Renesas SH7781 User Manual

Page 778

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15. Clock Pulse Generator (CPG)

Rev.1.00 Jan. 10, 2008 Page 748 of 1658
REJ09B0261-0100

15.5

Calculating the Frequency

Table 15.7 shows the relationship between the division ratio of divider 2 described for frequency
control register FRQCR1 and frequency display register FRQMR1, and the EXTAL input.

Table 15.7 Relationship Between the Division Ratio of Divider 2 and the Frequency

Frequency (for an input clock)

Division ratio of
divider 2

Clock operating mode 0 to 3

Clock operating mode 16 to 19

Ч 1/2

Ч 36

Ч 18

Ч 1/4

Ч 18

Ч 9

Ч 1/6

Ч 12

Ч 6

Ч 1/8

Ч 9

Ч 9/2

Ч 1/12

Ч 6

Ч 3

Ч 1/16

Ч 9/2

Ч 9/4

Ч 1/18

Ч 4

Ч 2

Ч 1/24

Ч 3

Ч 3/2

Ч 1/32

Ч 9/4

Ч 9/8

Ч 1/36

Ч 2

Ч 1

Ч 1/48

Ч 3/2

Ч 3/4

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