DF2437FV Renesas Electronics America, DF2437FV Datasheet - Page 460

• Manufacturer Part Number: DF2437FV
• Description: IC H8S/2437 MCU FLASH 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2400r

Specifications of DF2437FV

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 85
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

14.3
The duty measurement circuit has the following registers.
• Free-running counter (TWCNT)
• Input capture register (TWICR)
• Duty measurement control register 1 (TWCR1)
• Duty measurement control register 2 (TWCR2)
14.3.1
TWCNT is an 8-bit readable/writable up-counter. The free-running count operation is performed
by setting the FRC bit in TWCR1 to 1. When the START bit in TWCR2 is set to 1, TWCNT is
cleared and duty measurement is started. For details on duty measurement operation, see section
14.4, Operation. The clock source is selected by bits CKS2 to CKS0 in TWCR1. When TWCNT
overflows from H'FF to H'00, the OVF bit in TWCR2 is set to 1. TWCNT is initialized to H'00.
14.3.2
TWICR is an 8-bit read-only register. When the falling edge of the external event signal is
detected during duty measurement, the current TWCNT value is transferred. For details on duty
measurement operation, see section 14.4, Operation. TWICR is initialized to H'00.
Rev.2.00 May. 28, 2009 Page 420 of 732
REJ09B0059-0200
Register Descriptions
Free-Running Counter (TWCNT)
Input Capture Register (TWICR)