DF2345TE20 Renesas Electronics America, DF2345TE20 Datasheet - Page 85

• Manufacturer Part Number: DF2345TE20
• Description: MCU 5V 128K 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2345TE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 71
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2345TE20; HD64F2345TE20

Section 2 CPU
(2) Reset Exception Handling
After the RES pin has gone low and the reset state has been entered, when RES goes high again,
reset exception handling starts. The CPU enters the power-on reset state when the NMI pin is high,
or the manual reset state when the NMI pin is low. When reset exception handling starts the CPU
fetches a start address (vector) from the exception vector table and starts program execution from
that address. All interrupts, including NMI, are disabled during reset exception handling and after
it ends.
(3) Traces
Traces are enabled only in interrupt control mode 2. Trace mode is entered when the T bit of EXR
is set to 1. When trace mode is established, trace exception handling starts at the end of each
instruction.
At the end of a trace exception-handling sequence, the T bit of EXR is cleared to 0 and trace mode
is cleared. Interrupt masks are not affected.
The T bit saved on the stack retains its value of 1, and when the RTE instruction is executed to
return from the trace exception-handling routine, trace mode is entered again. Trace exception-
handling is not executed at the end of the RTE instruction.
Trace mode is not entered in interrupt control mode 0, regardless of the state of the T bit.
(4) Interrupt Exception Handling and Trap Instruction Exception Handling
When interrupt or trap-instruction exception handling begins, the CPU references the stack pointer
(ER7) and pushes the program counter and other control registers onto the stack. Next, the CPU
alters the settings of the interrupt mask bits in the control registers. Then the CPU fetches a start
address (vector) from the exception vector table and program execution starts from that start
address.
Figure 2.16 shows the stack after exception handling ends.
Rev. 4.00 Feb 15, 2006 page 59 of 900
REJ09B0291-0400