M37544G2AGP#U0 Renesas Electronics America, M37544G2AGP#U0 Datasheet - Page 40

• Manufacturer Part Number: M37544G2AGP#U0
• Description: IC 740 MCU OTP 8K 32LQFP
• Manufacturer: Renesas Electronics America
• Series: 740/38000r

Specifications of M37544G2AGP#U0

• Core Processor: 740
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SIO, UART/USART
• Peripherals: WDT
• Number Of I /o: 25
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: QzROM
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Reset Circuit
The 7544 group starts operation by the on-chip oscillator after sys-
tem is released from reset.
Accordingly, when the rising of power supply voltage passes 2.2V,
set the reset input voltage to become below 0.2Vcc (0.44V).
Moreover, switch CPU clock to the external oscillator after the ris-
ing of power supply voltage passes the minimum operation
voltage and after an oscillation is stabilized.
Note: The minimum operation voltage is decided by the division
REJ03B0108-0103
page 38 of 72
7544 Group (QzROM version)
Fig. 39 Timing diagram at reset
Clock from
on-chip oscillator
RING
ratio of an external oscillator's frequency and a CPU clock.
Decide on an external oscillator's oscillation stabilizing time
after fully evaluating an oscillator's stabilizing time used.
RESET
Address
RESET
SYNC
Data
φ
OUT
Rev.1.03
8-13 clock cycles
Mar 31, 2009
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Notes
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1 : An on-chip oscillator applies about RING•2 MHz, φ•250 kHz frequency clock
3 : These are all internal signals except RESET.
2 : The mark “?” means that the address is changeable depending on the previous state.
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at average of Vcc = 5 V.
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Fig. 38 Example of reset circuit
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RESET
RESET
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FFFC
AD
L
FFFD
V
V
AD
CC
CC
AD
H
H
Power source
voltage
Reset input
voltage
,AD
0 V
0 V
L
Note : Reset release voltage Vcc 2.2V
Reset address from the
vector table
Power source
voltage
detection circuit
Poweron
(Note)
0.2 V
CC