PIC18F85K22-I/PT Microchip Technology, PIC18F85K22-I/PT Datasheet - Page 75

• Manufacturer Part Number: PIC18F85K22-I/PT
• Description: IC, 8BIT MCU, PIC18F, 64MHZ, TQFP-80
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F85K22-I/PT

• Controller Family/series: PIC18
• No. Of I/o's: 69
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 64MHz
• No. Of Timers: 8
• Core Size: 8 Bit
• Program Memory Size: 32KB
• Core Processor: PIC
• Speed: 64MHz
• Connectivity: EBI/EMI, I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5.2
The MCLR pin provides a method for triggering a hard
external Reset of the device. A Reset is generated by
holding the pin low. PIC18 extended microcontroller
devices have a noise filter in the MCLR Reset path
which detects and ignores small pulses.
The MCLR pin is not driven low by any internal Resets,
including the WDT.
5.3
A Power-on Reset condition is generated on-chip
whenever V
allows the device to start in the initialized state when
V
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 k to 10 k) to V
eliminate external RC components usually needed to
create a Power-on Reset delay. A minimum rise rate for
V
time, see
When the device starts normal operation (exiting the
Reset condition), device operating parameters (such
as voltage, frequency and temperature) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
Power-on Reset events are captured by the POR bit
(RCON<1>). The state of the bit is set to ‘0’ whenever
a Power-on Reset occurs and does not change for any
other Reset event. POR is not reset to ‘1’ by any
hardware event. To capture multiple events, the user
manually resets the bit to ‘1’ in software following any
Power-on Reset.
5.4
The PIC18F87K22 family has four BOR Power modes:
• High-Power BOR
• Medium Power BOR
• Low-Power BOR
• Zero-Power BOR
Each power Mode is selected by the BORPWR<1:0>
bits setting (CONFIG2L<6:5>). For low, medium and
high-power BOR, the module monitors the V
ing on the BORV<1:0> setting (CONFIG1L<3:2>). A
BOR event re-arms the Power-on Reset. It also causes
a Reset, depending on which of the trip levels has been
set: 1.8V, 2V, 2.7V or 3V.
BOR
(CONFIG2L<2:1>) and the SBOREN bit (RCON<6>).
Typical power consumption is listed as Parameter
in
 2009-2011 Microchip Technology Inc.
DD
DD
Section 31.0 “Electrical
is adequate for operation.
is specified (Parameter D004). For a slow rise
is
Master Clear (MCLR)
Power-on Reset (POR)
Brown-out Reset (BOR)
Figure
DD
enabled
rises above a certain threshold. This
5-2.
by
Characteristics”.
the
BOREN<1:0>
DD
DD
. This will
depend-
D022A
bits
PIC18F87K22 FAMILY
In Zero-Power BOR (ZPBORMV), the module monitors
the V
ZPBORMV does not cause a Reset, but re-arms the
POR.
The BOR accuracy varies with its power level. The lower
the power setting, the less accurate the BOR trip levels
are. Therefore, the high-power BOR has the highest
accuracy and the low-power BOR has the lowest
accuracy. The trip levels (BV
rent consumption
Power-Down and Supply Current PIC18F87K22
Family
below BV
Section 31.0 “Electrical
FIGURE 5-2:
5.4.1
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.
LP-BOR cannot be detected with the BOR bit in the
RCON register. LP-BOR can rearm the POR and can
cause a Power-on Reset.
Note 1: External Power-on Reset circuit is required
DD
V
2: R < 40 k is recommended to make sure that
3: R1  1 k will limit any current flowing into
(Industrial/Extended)”) and time required
DD
voltage and re-arms the POR at about 2V.
DD
D
DETECTING BOR
only if the V
The diode, D, helps discharge the capacitor
quickly when V
the voltage drop across R does not violate
the device’s electrical specification.
MCLR from external capacitor, C, in the event
of
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
(T
BOR
V
DD
MCLR/V
R
(Section 31.2 “DC Characteristics:
C
, Parameter 35) can all be found in
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW V
DD
PP
Characteristics”.
R1
DD
power-up slope is too slow.
DD
pin
powers down.
, Parameter D005), cur-
DD
MCLR
PIC18F87K22
breakdown
POWER-UP)
DS39960D-page 75
due
to