PIC18C252-I/SO Microchip Technology, PIC18C252-I/SO Datasheet - Page 178

• Manufacturer Part Number: PIC18C252-I/SO
• Description: IC MCU OTP 16KX16 A/D 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C252-I/SO

• Core Size: 8-Bit
• Program Memory Size: 32KB (16K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Type: OTP
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Controller Family/series: PIC18
• No. Of I/o's: 24
• Ram Memory Size: 1536Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Interface: I2C, SPI, USART
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 23
• Interface Type: I2C/SPI/USART
• On-chip Adc: 5-chx10-bit
• Number Of Timers: 4
• Embedded Interface Type: I2C, SPI, USART
• Rohs Compliant: Yes
• Processor Series: PIC18C
• Core: PIC
• Data Ram Size: 1536 B
• Maximum Clock Frequency: 40 MHz
• 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: ICE2000, DM163022, DV164136
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MILI3DB18C452 - BOARD DAUGHTER ICEPIC3309-1073 - ADAPTER 28-SOIC TO 28-SOIC309-1024 - ADAPTER 28-SOIC TO 28-DIP309-1023 - ADAPTER 28-SOIC TO 28-DIP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC18CXX2
17.2
Depending on the power source for the device voltage,
the voltage normally decreases relatively slowly. This
means that the LVD module does not need to be con-
stantly operating. To decrease the current require-
ments, the LVD circuitry only needs to be enabled for
short periods, where the voltage is checked. After
doing the check, the LVD module may be disabled.
Each time that the LVD module is enabled, the circuitry
requires some time to stabilize. After the circuitry has
stabilized, all status flags may be cleared. The module
will then indicate the proper state of the system.
FIGURE 17-4:
DS39026C-page 176
Internally Generated
Internally Generated
Reference stable
Reference stable
Operation
CASE 1:
CASE 2:
Enable LVD
Enable LVD
LVDIF
LVDIF
V
V
DD
DD
LOW VOLTAGE DETECT WAVEFORMS
50 ms
50 ms
LVDIF may not be set
The following steps are needed to set up the LVD module:
1.
2.
3.
4.
5.
6.
Figure 17-4 shows typical waveforms that the LVD
module may be used to detect.
LVDIF cleared in software,
LVDIF remains set since LVD condition still exists
Write the value to the LVDL3:LVDL0 bits (LVD-
CON register), which selects the desired LVD
Trip Point.
Ensure that LVD interrupts are disabled (the
LVDIE bit is cleared, or the GIE bit is cleared).
Enable the LVD module (set the LVDEN bit in
the LVDCON register).
Wait for the LVD module to stabilize (the IRVST
bit to become set).
Clear the LVD interrupt flag, which may have
falsely become set until the LVD module has
stabilized (clear the LVDIF bit).
Enable the LVD interrupt (set the LVDIE and the
GIE bits).
LVDIF cleared in software
2000 Microchip Technology Inc.
LVDIF cleared in software
V
V
LVD
LVD