DF2437FV Renesas Electronics America, DF2437FV Datasheet - Page 89

• 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: -

2.8
The H8S/2600 CPU has five main processing states: the reset state, exception handling state,
program execution state, bus-released state, and program stop state. Figure 2.13 indicates the state
transitions.
• Reset State
• Exception-Handling State
• Program Execution State
• Bus-Released State
• Program stop state
The CPU and on-chip peripheral modules are all initialized and stop. When the RES input goes
low, all current processing stops and the CPU enters the reset state. All interrupts are masked
in the reset state. Reset exception handling starts when the RES signal changes from low to
high. For details, refer to section 4, Exception Handling.
The reset state can also be entered by a watchdog timer overflow.
The exception-handling state is a transient state that occurs when the CPU alters the normal
processing flow due to an exception source, such as, a reset, trace, interrupt, or trap instruction.
The CPU fetches a start address (vector) from the exception-handling vector table and
branches to that address. For further details, refer to section 4, Exception Handling.
In this state the CPU executes program instructions in sequence.
In a product which has a bus mastership other than the CPU, such as a direct memory access
controller (DMAC) and a data transfer controller (DTC), the bus-released state occurs when
the bus has been released in response to a bus request from a bus mastership other than the
CPU. While the bus is released, the CPU halts operations.
This is a power-down state in which the CPU stops operating. The program stop state occurs
when a SLEEP instruction is executed or the CPU enters hardware standby mode. For further
details, refer to section 22, Power-Down Modes.
Processing States
Rev.2.00 May. 28, 2009 Page 49 of 732
REJ09B0059-0200