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FUJITSU MB91460 SERIES FR60 User Manual

Page 208

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Chapter 13 Clock Control

4.Registers

• After setting “11B” (subclock), insert one or more NOP instructions.

• Selecting the subclock as the clock source is prohibited while the subclock selection enable bit (SCKEN)

is “0”. (See table for details.)

Example: To select the subclock after an INIT reset, first write “01

B

” and then write “11

B

” (subclock).

(See “

8. Caution (Page No.205)

”.)

Table 4-1 Cases When the CLKS1 and CLKS0 Bits May or May Not be Modified

Modify permitted

Modify not permitted

“00”

→ “01” or “10”

“00”

→ “11”

“01”

→ “11” or “00”

“01”

→ “10”

“10”

→ “00”

“10”

→ “01” or “11”

“11”

→ “01”

“11”

→ “00” or “10”