PIC18LF8490-I/PT Microchip Technology, PIC18LF8490-I/PT Datasheet - Page 56

• 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

PIC18F6390/6490/8390/8490
4.4
PIC18F6390/6490/8390/8490 devices implement a
BOR circuit that provides the user with a number of
configuration and power-saving options. The BOR is
controlled
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) for greater than T
the device. A Reset may or may not occur if V
below V
Brown-out Reset until V
If the Power-up Timer is enabled, it will be invoked after
V
Reset
(parameter 33). If V
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
Timer will execute the additional time delay.
BOR
independently configured. Enabling the 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:
DS39629C-page 54
DD
BOREN1
BOR Configuration
rises above V
0
0
1
1
and
BOR
for
Brown-out Reset (BOR)
SOFTWARE ENABLED BOR
for less than T
an
the
by
BOREN0
BOR CONFIGURATIONS
DD
additional
BOR
Power-up
0
1
0
1
DD
rises above V
the
DD
; it then will keep the chip in
drops below V
BOR
BOR
DD
rises above V
(RCON<6>)
Unavailable
Unavailable
Unavailable
(parameter 35) will reset
BORV1:BORV0
SBOREN
below V
Available
Status of
. The chip will remain in
time
Timer
BOR
delay,
BOR
, the Power-up
BOR
(PWRT)
BOR
(parameter
BOR is disabled; must be enabled by reprogramming the Configuration
bits.
BOR is enabled in software; operation controlled by SBOREN.
BOR is enabled in hardware and active during the Run and Idle modes,
disabled during Sleep mode.
BOR is enabled in hardware; must be disabled by reprogramming the
Configuration bits.
.
while the
DD
T
PWRT
falls
and
are
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 the BOR configuration. It also allows the user
to tailor device power consumption in software by
eliminating 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.