HD6417750SF200V Renesas Electronics America, HD6417750SF200V Datasheet - Page 395

• Manufacturer Part Number: HD6417750SF200V
• Description: MPU 3V 16K PB-FREE 208-QFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7750r

Specifications of HD6417750SF200V

• Core Processor: SH-4
• Core Size: 32-Bit
• Speed: 200MHz
• Connectivity: EBI/EMI, FIFO, SCI, SmartCard
• Peripherals: DMA, POR, WDT
• Number Of I /o: 28
• Program Memory Type: ROMless
• Ram Size: 24K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 2.07 V
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 208-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

10.11
10.11.1 Invalid Manual Reset Triggered by Watchdog Timer (SH7750 and SH7750S)
Under certain conditions the watchdog timer (WDT) may trigger an invalid manual reset.
Conditions Under which Problem Occurs: The internal WDT triggers an invalid manual reset
when all of the following four conditions are satisfied.
1. After the WDT overflows, regardless of the values of the WT/IT and RSTS bits in WTCSR.
2. Before the counter (WTCNT) is incremented by the clock specified by the WTCSR.CKS bit.
3. The value of at least one of the TME, WT/IT, and RSTS bits in WTCSR is 0.
4. A value of 1 is written to the TME, WT/IT, and RSTS bits in WTCSR.
Workaround: A workaround for this problem is to use software to increment WTCNT before
writing 1 to the TME, WT/IT, and RSTS bits in WTCSR. Specific lines of code for this purpose
are listed below.
Example: Add the following lines of code before the instructions for writing 1 to the TME,
WT/IT, and RSTS bits in WTCSR.
LOOP_WDT:
Usage Notes
MOV.L #WTCNT,R7
MOV.W #H'5A00,R8
MOV.W R8,@R7
MOV.L #WTCSR,R9
MOV.W #H'A580,R10
MOV.W R10,@R9
MOV.B @R7,R0
CMP/EQ #H'00, R0
BT
LOOP_WDT
Rev.7.00 Oct. 10, 2008 Page 309 of 1074
Section 10 Clock Oscillation Circuits
REJ09B0366-0700