PIC18LF8490-I/PT Microchip Technology, PIC18LF8490-I/PT Datasheet - Page 55

• Manufacturer Part Number: PIC18LF8490-I/PT
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,TQFP,80PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF8490-I/PT

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, LCD, POR, PWM, WDT
• Number Of I /o: 66
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TFQFP
• Processor Series: PIC18LF
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: SPI, I2C, EUSART, AUSART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 66
• Number Of Timers: 1 x 8
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136, DM163028
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

4.2
The MCLR pin provides a method for triggering a hard
external Reset of the device. A Reset is generated by
holding the pin low. PIC18 Extended MCU devices
have a noise filter in the MCLR Reset path which
detects and ignores small pulses.
The MCLR pin is not driven low by any internal Resets,
including the WDT.
In PIC18F6390/6490/8390/8490 devices, the MCLR
input can be disabled with the MCLRE Configuration
bit. When MCLR is disabled, the pin becomes a digital
input. See Section 9.7 “PORTG, TRISG and LATG
Registers” for more information.
4.3
A Power-on Reset pulse is generated on-chip
whenever V
allows the device to start in the initialized state when
V
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 kΩ to 10 kΩ) to V
eliminate external RC components usually needed to
create a Power-on Reset delay. A minimum rise rate for
V
time, see Figure 4-2.
When the device starts normal operation (i.e., exits the
Reset
(voltage, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
POR events are captured by the POR bit (RCON<1>).
The state of the bit is set to ‘0’ whenever a Power-on
Reset occurs; it does not change for any other Reset
event. POR is not reset to ‘1’ by any hardware event.
To capture multiple events, the user manually resets
the bit to ‘1’ in software following any Power-on Reset.
© 2007 Microchip Technology Inc.
DD
DD
is adequate for operation.
is specified (parameter D004). For a slow rise
condition),
Master Clear (MCLR)
Power-on Reset (POR)
DD
rises above a certain threshold. This
device
operating
DD
parameters
. This will
PIC18F6390/6490/8390/8490
FIGURE 4-2:
Note 1: External Power-on Reset circuit is required
V
2: R < 40 kΩ is recommended to make sure that
3: R1 ≥ 1 kΩ will limit any current flowing into
DD
D
only if the V
The diode D helps discharge the capacitor
quickly when V
the voltage drop across R does not violate
the device’s electrical specification.
MCLR from external capacitor C, in the event
of MCLR/V
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
V
DD
R
C
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW V
DD
PP
DD
R1
power-up slope is too slow.
pin breakdown, due to
powers down.
DD
PIC18FXXXX
MCLR
POWER-UP)
DS39629C-page 53