PIC18F87K22-I/PTRSL Microchip Technology Inc., PIC18F87K22-I/PTRSL Datasheet - Page 76

• Manufacturer Part Number: PIC18F87K22-I/PTRSL
• Description: 128kB Flash, 4kB RAM, 1kB EE, nanoWatt XLP, GP, 80 TQFP 12x12x1mm TRAY
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F87K22-I/PTRSL

• A/d Inputs: 24-Channel, 12-Bit
• Comparators: 3
• Cpu Speed: 16 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 69
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 80-pin TQFP
• Programmable Memory: 128K Bytes
• Ram Size: 3.8K Bytes
• Speed: 64 MHz
• Temperature Range: –40 to 125 °C
• Timers: 6-8-bit, 5-16-bit
• Voltage, Range: 1.8-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F87K22 FAMILY
5.5
The Configuration Mismatch (CM) Reset is designed to
detect, and attempt to recover from, random, memory
corrupting events. These include Electrostatic Discharge
(ESD) events that can cause widespread, single bit
changes throughout the device and result in catastrophic
failure.
In PIC18F87K22 family Flash devices, the device
Configuration registers (located in the configuration
memory space) are continuously monitored during
operation by comparing their values to complimentary
shadow registers. If a mismatch is detected between
the two sets of registers, a CM Reset automatically
occurs. These events are captured by the CM bit
(RCON<5>). The state of the bit is set to ‘0’ whenever
a CM event occurs and does not change for any other
Reset event.
A CM Reset behaves similarly to a Master Clear Reset,
RESET instruction, WDT time-out or Stack Event Reset.
As with all hard and power Reset events, the device
Configuration Words are reloaded from the Flash
Configuration Words in program memory as the device
restarts.
FIGURE 5-3:
DS39960C-page 76
INTERNAL RESET
PWRT TIME-OUT
INTERNAL POR
Configuration Mismatch (CM)
MCLR
V
DD
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO V
T
PWRT
5.6
PIC18F87K22 family devices incorporate an on-chip
Power-up Timer (PWRT) to help regulate the Power-on
Reset process. The PWRT is enabled by setting the
PWRTEN bit (CONFIG2L<0>). The main function is to
ensure that the device voltage is stable before code is
executed.
The Power-up Timer (PWRT) of the PIC18F87K22
family devices is a 13-bit counter that uses the
LF-INTOSC source as the clock input. This yields an
approximate time interval of 2,048 x 32 s = 66 ms.
While the PWRT is counting, the device is held in
Reset.
The power-up time delay depends on the LF-INTOSC
clock and will vary from chip-to-chip due to temperature
and process variation. See DC Parameter
details.
5.6.1
If enabled, the PWRT time-out is invoked after the POR
pulse has cleared. The total time-out will vary based on
the status of the PWRT.
Figure 5-5
sequences on power-up with the Power-up Timer
enabled.
Since the time-outs occur from the POR pulse, if
MCLR is kept low long enough, the PWRT will expire.
Bringing MCLR high will begin execution immediately
(Figure
synchronizing more than one PIC18 device operating
in parallel.
5-5). This is useful for testing purposes, or for
Power-up Timer (PWRT)
TIME-OUT SEQUENCE
and
Figure 5-6
 2011 Microchip Technology Inc.
DD
, V
Figure
DD
all
RISE < T
depict
5-3,
Figure
PWRT
time-out
33
5-4,
)
for