HD6475328-CP10 HITACHI [Hitachi Semiconductor], HD6475328-CP10 Datasheet - Page 221

• Manufacturer Part Number: HD6475328-CP10
• Description: original Hitachi CMOS microcomputer unit (MCU)
• Manufacturer: HITACHI [Hitachi Semiconductor]

Table 10-5 Effect of Changing Internal Clock Sources
No.
1
2
3
The switching of clock sources is regarded as a falling edge that increments the FRC.
Description
Low
CKS1 and CKS0 are
rewritten while both
clock sources are Low.
Low
CKS1 and CKS0 are
rewritten while old
clock source is Low and
new clock source is High.
High
CKS1 and CKS0 are
rewritten while old
clock source is High and
new clock source is Low.
Low:
High:
Low:
Timing Chart
Old clock
source
New clock
source
FRC clock
pulse
FRC
Old clock
source
New clock
source
FRC clock
pulse
FRC
Old clock
source
New clock
source
FRC clock
pulse
FRC
204
N
N
N
CKS rewrite
N + 1
CKS rewrite
N + 1
N + 1
*
N + 2
N + 2