PIC18C801-I/L Microchip Technology, PIC18C801-I/L Datasheet - Page 203

• Manufacturer Part Number: PIC18C801-I/L
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,84PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C801-I/L

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Type: ROMless
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 84-PLCC
• Processor Series: PIC18C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: 3-Wire, I2C, SPI, USART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 47
• Number Of Timers: 1 x 16 bit
• 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: DV164005, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCXLT84L1 - SOCKET TRANSITION ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC18C801-I/LR; PIC18C801-I/LR; PIC18C801I/L

18.0
In many applications, the ability to determine if the
device voltage (V
is a desirable feature. A window of operation for the
application can be created, where the application soft-
ware can do "housekeeping tasks", before the device
voltage exits the valid operating range. This can be
done using the Low Voltage Detect module.
This module is software programmable circuitry, where
a device voltage trip point can be specified (internal ref-
erence voltage or external voltage input). When the
voltage of the device becomes lower than the specified
point, an interrupt flag is set. If the interrupt is enabled,
the program execution will branch to the interrupt vec-
tor address and the software can then respond to that
interrupt source.
The Low Voltage Detect circuitry is completely under
software control. This allows the circuitry to be "turned
off" by the software, which minimizes the current con-
sumption for the device.
Figure 18-1 shows a possible application voltage curve
(typically for batteries). Over time, the device voltage
decreases. When the device voltage equals voltage V
the LVD logic generates an interrupt. This occurs at time
T
device voltage is no longer in valid operating range, to
shut-down the system. Voltage point V
valid operating voltage specification. This occurs at time
T
FIGURE 18-1:
A
B
2001 Microchip Technology Inc.
. The application software then has the time, until the
. T
Legend:
V
V
B
A
B
- T
V
V
A
B
LOW VOLTAGE DETECT
A
= LVD trip point
= Minimum valid device operating range
is the total time for shut-down.
DD
) is below a specified voltage level
TYPICAL LOW VOLTAGE
DETECT APPLICATION
Time
T
A
B
T
is the minimum
B
Advance Information
A
,
Figure 18-2 shows the block diagram for the LVD mod-
ule. A comparator uses an internally generated refer-
ence voltage as the set point. When the selected tap
output of the device voltage crosses the set point (is
lower than), the LVDIF bit (PIR registers) is set.
Each node in the resister divider represents a “trip
point” voltage. The “trip point” voltage is the minimum
supply voltage level at which the device can operate,
before the LVD module asserts an interrupt. When the
supply voltage is equal to the trip point, the voltage
tapped off of the resistor array (or external LVDIN input
pin) is equal to the voltage generated by the internal
voltage reference module. The comparator then gener-
ates an interrupt signal setting the LVDIF bit. This volt-
age is software programmable to any one of 16 values
(see Figure 18-2). The trip point is selected by
programming the LVDL3:LVDL0 bits (LVDCON<3:0>).
FIGURE 18-2:
LVDEN
V
DD
PIC18C601/801
LVDIN
LOW VOLTAGE DETECT
(LVD) BLOCK DIAGRAM
Internally Generated
Reference Voltage
DS39541A-page 203
LVD Control
Register
LVDIF