HD64F36912GFH Renesas Electronics America, HD64F36912GFH Datasheet - Page 322

• Manufacturer Part Number: HD64F36912GFH
• Description: IC H8 MCU FLASH 8K 32-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300H Tinyr

Specifications of HD64F36912GFH

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 12MHz
• Connectivity: I²C, SCI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 17 Band-Gap Circuit, Power-On Reset, and Low-Voltage Detection Circuits
17.3.2
(1)
Figure 17.4 shows the timing of the operation of the LVDR circuit. The LVDR circuit is enabled
after a power-on reset is released. To cancel the LVDR circuit, first the LVDRE bit in LVDCR
should be cleared to 0 and then the LVDE bit in LVDCR and, if necessary, the BGRE bit should
be cleared to 0. The LVDE and the BGRE bits must not be cleared to 0 simultaneously with the
LVDRE bit because incorrect operation may occur. To restart the LVDR circuit, set the LVDE bit
and the BGRE bit to 1, wait for 50 s (t
and the low-voltage-detection power supply have settled, then set the LVDRE bit to 1. After that,
the output settings of ports must be made.
When the power-supply voltage falls below the Vreset voltage (2.3 V or 3.6 V (Typ.)), the LVDR
circuit clears the LVDRES signal to 0, and resets prescaler S. The low-voltage detection reset state
remains in place until a power-on reset is generated. When the power-supply voltage rises above
the Vreset voltage again, prescaler S starts counting. It counts 131,072 clock ( ) cycles, and then
releases the internal reset signal. In this case, the LVDE, BGRE, VDDII, LVDSEL, and LVDRE
bits in LVDCR are not initialized.
Note that if the power supply voltage (Vcc) falls below V
point, the low-voltage detection reset may not occur.
If the power supply voltage (Vcc) falls below Vpor = 100 mV, a power-on reset occurs.
Rev. 3.00 Sep. 14, 2006 Page 292 of 408
REJ09B0105-0300
RES
Vcc
PSS-reset
signal
OVF
Internal reset
signal
LVDR (Reset by Low Voltage Detection) Circuit
Low-Voltage Detection Circuit
Vpor
t
PWON
Figure 17.3 Operational Timing of Power-On Reset Circuit
PSS counter starts
131,072 cycles
LVDON
Reset released
) given by a software timer until the reference voltage
LVDRmin
= 1.0 V and then rises from that
Vss
Vss