HD64F3644H Renesas Electronics America, HD64F3644H Datasheet - Page 290

• Manufacturer Part Number: HD64F3644H
• Description: IC H8 MCU FLASH 32K 64-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Lr

Specifications of HD64F3644H

• Core Processor: H8/300L
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI
• Peripherals: PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 64-QFP
• Package: 64PQFP
• Family Name: H8
• Maximum Speed: 8 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 45
• Interface Type: SCI
• On-chip Adc: 8-chx8-bit
• Number Of Timers: 4
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 9 Timers
4. Internal clock switching and counter operation
Table 9.19 Internal Clock Switching and FRC Operation
No.
1
2
Rev. 6.00 Sep 12, 2006 page 268 of 526
REJ09B0326-0600
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 ( ). 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.
Clock Levels Before
and After Modifying
Bits CKS1 and CKS0
Goes from low level
to low level
Goes from low
to high
FRC Operation
Clock before
switching
Clock after
switching
Count clock
FRC
Clock before
switching
Clock after
switching
Count clock
FRC
Write to CKS1 and CKS0
N
N
N + 1
Write to CKS1 and CKS0
N + 1
N + 2