PIC18F4580T-I/ML Microchip Technology, PIC18F4580T-I/ML Datasheet - Page 50

• Manufacturer Part Number: PIC18F4580T-I/ML
• Description: IC PIC MCU FLASH 16KX16 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4580T-I/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

PIC18F2480/2580/4480/4580
5.4
PIC18F2480/2580/4480/4580 devices implement a
BOR circuit that provides the user with a number of
configuration and power-saving options. The BOR is
controlled by the BORV<1:0> and BOREN<1:0>
Configuration bits. There are a total of four BOR
configurations which are summarized in Table 5-1.
The BOR threshold is set by the BORV<1:0> bits. If
BOR is enabled (any values of BOREN<1:0>, except
‘00’), any drop of V
for greater than T
device. A Reset may or may not occur if V
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 a Brown-out Reset
does not automatically enable the PWRT.
5.4.1
When BOREN<1:0> = 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 5-1:
DS39637D-page 50
BOR
DD
BOREN1
BOR Configuration
rises above V
0
0
1
1
for less than T
and
for
Brown-out Reset (BOR)
SOFTWARE ENABLED BOR
an
the
BOREN0
BOR CONFIGURATIONS
DD
BOR
additional
BOR
Power-on
DD
0
1
0
1
DD
rises above V
BOR
below V
DD
; it then will keep the chip in
(parameter 35) will reset the
drops below V
. The chip will remain in
rises above V
(RCON<6>)
Unavailable
Unavailable
Unavailable
SBOREN
Available
Status of
time
BOR
Timer
BOR
(parameter D005)
delay,
, the Power-up
BOR
(PWRT)
DD
BOR
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.
falls below
.
while the
T
PWRT
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 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.
5.4.2
When Brown-out Reset is enabled, the BOR bit always
resets to ‘0’ on any Brown-out Reset or Power-on
Reset event. This makes it difficult to determine if a
Brown-out Reset 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 Power-on Reset event. IF BOR
is ‘0’ while POR is ‘1’, it can be reliably assumed that a
Brown-out Reset event has occurred.
5.4.3
When BOREN<1:0> = 10, the BOR remains under
hardware
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 Brown-out Reset voltage level is still
set by the BORV<1:0> Configuration bits.
It cannot be changed in software.
DETECTING BOR
DISABLING BOR IN SLEEP MODE
control
and
© 2009 Microchip Technology Inc.
operates
as
previously