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Section 9 Timers
Rev. 6.00 Sep 12, 2006 page 268 of 526
REJ09B0326-0600
4. Internal clock switching and counter operation
Depending on the timing, FRC may be incremented by a switch between different internal
clock sources. Table 9.19 shows the relation between internal clock switchover timing (by
writing to bits CKS1 and CKS0) and FRC operation.
When FRC is internally clocked, an increment pulse is generated from the falling edge of an
internal clock signal, which is divided from the system clock (
φ
). For this reason, in a case like
No. 3 in table 9.19 where the switch is from a high clock signal to a low clock signal, the
switchover is seen as a falling edge, causing FRC to increment.
FRC can also be incremented by a switch between internal and external clocks.
Table 9.19 Internal Clock Switching and FRC Operation
No.
Clock Levels Before
and After Modifying
Bits CKS1 and CKS0
FRC Operation
1
Goes from low level
to low level
N + 1
Clock before
switching
Clock after
switching
Count clock
FRC
Write to CKS1 and CKS0
N
2
Goes from low
to high
N + 1
N + 2
Clock before
switching
Clock after
switching
Count clock
FRC
Write to CKS1 and CKS0
N
Содержание F-ZTAT H8/3642A Series
Страница 6: ...Rev 6 00 Sep 12 2006 page iv of xx ...
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Страница 21: ...Rev 6 00 Sep 12 2006 page xix of xx Appendix E Product Code Lineup 522 Appendix F Package Dimensions 524 ...
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Страница 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Страница 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Страница 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Страница 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Страница 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Страница 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...