PIC18F2455-I/SP Microchip Technology, PIC18F2455-I/SP Datasheet - Page 48

• Manufacturer Part Number: PIC18F2455-I/SP
• Description: IC PIC MCU FLASH 12KX16 28DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2455-I/SP

• Program Memory Type: FLASH
• Program Memory Size: 24KB (12K x 16)
• Package / Case: 28-DIP (0.300", 7.62mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 24
• Eeprom Size: 256 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: SPI/I2C/EAUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163014, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10-ch x 10-bit
• Package: 28SPDIP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: I3-DB18F4550 - BOARD DAUGHTER ICEPIC3DM163025 - PIC DEM FULL SPEED USB DEMO BRDDVA18XP280 - DEVICE ADAPTER 18F2220 PDIP 28LD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2455/2550/4455/4550
4.4
PIC18F2455/2550/4455/4550 devices implement a
BOR circuit that provides the user with a number of
configuration and power-saving options. The BOR
is
BOREN1:BOREN0 Configuration bits. There are a total
of four BOR configurations which are summarized in
Table 4-1.
The BOR threshold is set by the BORV1:BORV0 bits. If
BOR is enabled (any values of BOREN1:BOREN0
except ‘00’), any drop of V
D005, Section
greater than T
reset the device. A Reset may or may not occur if V
falls below V
remain in Brown-out Reset until V
If the Power-up Timer is enabled, it will be invoked after
V
Reset
(parameter 33, Table 28-12). If V
while the Power-up Timer is running, the chip will go
back into a Brown-out Reset and the Power-up Timer
will be initialized. Once V
Power-up Timer will execute the additional time delay.
BOR
independently configured. Enabling BOR Reset does
not automatically enable the PWRT.
4.4.1
When BOREN1:BOREN0 = 01, the BOR can be
enabled or disabled by the user in software. This is
done with the control bit, SBOREN (RCON<6>).
Setting SBOREN enables the BOR to function as
previously described. Clearing SBOREN disables the
BOR entirely. The SBOREN bit operates only in this
mode; otherwise, it is read as ‘0’.
TABLE 4-1:
DS39632D-page 46
DD
BOREN1
BOR Configuration
controlled
rises above V
0
0
1
1
and
for
Brown-out Reset (BOR)
SOFTWARE ENABLED BOR
BOR
an
the
BOR
BOREN0
BOR CONFIGURATIONS
by
28.1 “DC Characteristics”) for
for less than T
additional
BOR
Power-on
0
1
0
1
(parameter 35, Table 28-12) will
; it then will keep the chip in
the
DD
DD
(RCON<6>)
Unavailable
Unavailable
Unavailable
SBOREN
Available
below V
Status of
BORV1:BORV0
rises above V
time
Timer
DD
DD
BOR
rises above V
drops below V
delay,
BOR
. The chip will
(PWRT)
(parameter
BOR disabled; must be enabled by reprogramming the Configuration bits.
BOR enabled in software; operation controlled by SBOREN.
BOR enabled in hardware in Run and Idle modes, disabled during Sleep
mode.
BOR enabled in hardware; must be disabled by reprogramming the
Configuration bits.
BOR
T
PWRT
BOR
, the
and
BOR
Preliminary
are
DD
.
Placing the BOR under software control gives the user
the additional flexibility of tailoring the application to its
environment without having to reprogram the device to
change BOR configuration. It also allows the user to
tailor device power consumption in software by elimi-
nating the incremental current that the BOR consumes.
While the BOR current is typically very small, it may
have some impact in low-power applications.
4.4.2
When BOR is enabled, the BOR bit always resets to ‘0’
on any BOR or POR event. This makes it difficult to
determine if a BOR event has occurred just by reading
the state of BOR alone. A more reliable method is to
simultaneously check the state of both POR and BOR.
This assumes that the POR bit is reset to ‘1’ in software
immediately after any POR event. IF BOR is ‘0’ while
POR is ‘1’, it can be reliably assumed that a BOR event
has occurred.
4.4.3
When BOREN1:BOREN0 = 10, the BOR remains
under hardware control and operates as previously
described. Whenever the device enters Sleep mode,
however, the BOR is automatically disabled. When the
device returns to any other operating mode, BOR is
automatically re-enabled.
This mode allows for applications to recover from
brown-out situations, while actively executing code,
when the device requires BOR protection the most. At
the same time, it saves additional power in Sleep mode
by eliminating the small incremental BOR current.
Note:
BOR Operation
Even when BOR is under software control,
the BOR Reset voltage level is still set by
the BORV1:BORV0 Configuration bits. It
cannot be changed in software.
DETECTING BOR
DISABLING BOR IN SLEEP MODE
© 2007 Microchip Technology Inc.