HD64F3437TFI16V Renesas Electronics America, HD64F3437TFI16V Datasheet - Page 218

• Manufacturer Part Number: HD64F3437TFI16V
• Description: MCU FLASH 60K 100-TQFP
• Manufacturer: Renesas Electronics America

Specifications of HD64F3437TFI16V

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Increment Caused by Changing of Internal Clock Source: When an internal clock source is
changed, the changeover may cause FRC to increment. This depends on the time at which the
clock select bits (CKS1 and CKS0) are rewritten, as shown in table 8.5.
The pulse that increments FRC is generated at the falling edge of the internal clock source. If
clock sources are changed when the old source is high and the new source is low, as in case no. 3
in table 8.5, the changeover generates a falling edge that triggers the FRC increment clock pulse.
Switching between an internal and external clock source can also cause FRC to increment.
Table 8.5
No.
1
2
186
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.
Effect of Changing Internal Clock Sources
low:
high:
Timing
Old clock
source
New clock
source
FRC clock
pulse
FRC
Old clock
source
New clock
source
FRC clock
pulse
FRC
N
N
CKS rewrite
N + 1
CKS rewrite
N + 1
N + 2