HD64F3644DV Renesas Electronics America, HD64F3644DV Datasheet - Page 108

• Manufacturer Part Number: HD64F3644DV
• Description: IC H8/3644 MCU FLASH 64QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Lr

Specifications of HD64F3644DV

• 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: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 4 Clock Pulse Generators
In standby mode, watch mode, subactive mode, and subsleep mode, the system clock pulse
generator stops. Prescaler S also stops and is initialized to H'0000.
The CPU cannot read or write prescaler S.
The output from prescaler S is shared by the on-chip peripheral modules. The divider ratio can be
set separately for each on-chip peripheral function.
In active (medium-speed) mode the clock input to prescaler S is determined by the division factor
designated by MA1 and MA0 in SYSCR1.
Prescaler W (PSW): Prescaler W is a 5-bit counter using a 32.768 kHz signal divided by 4 (
/4)
W
as its input clock.
Prescaler W is initialized to H'00 by a reset, and starts counting on exit from the reset state.
Even in standby mode, watch mode, subactive mode, or subsleep mode, prescaler W continues
functioning so long as clock signals are supplied to pins X
and X
.
1
2
Prescaler W can be reset by setting 1s in bits TMA3 and TMA2 of timer mode register A (TMA).
Output from prescaler W can be used to drive timer A, in which case timer A functions as a time
base for timekeeping.
4.5
Note on Oscillators
Oscillator characteristics are closely related to board design and should be carefully evaluated by
the user, referring to the examples shown in this section. Oscillator circuit constants will differ
depending on the oscillator element, stray capacitance in its interconnecting circuit, and other
factors. Suitable constants should be determined in consultation with the oscillator element
manufacturer. Design the circuit so that the oscillator element never receives voltages exceeding
its maximum rating.
Rev. 6.00 Sep 12, 2006 page 86 of 526
REJ09B0326-0600