MA180025 Microchip Technology, MA180025 Datasheet - Page 56

• Manufacturer Part Number: MA180025
• Description: MODULE PLUG-IN PIC18F87J90 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180025

• Accessory Type: Plug-In Module (PIM) - PIC18F87J90
• Product: Microcontroller Modules
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PICDEM LCD 2 Demonstration Board (DM163030)
• For Use With: DM163030 - KIT DEV PICDEM LCD2
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F87J90 FAMILY
5.6
PIC18F87J90 family devices incorporate an on-chip
Power-up Timer (PWRT) to help regulate the Power-on
Reset process. The PWRT is always enabled. The
main function is to ensure that the device voltage is
stable before code is executed.
The Power-up Timer (PWRT) of the PIC18F87J90 fam-
ily devices is an 11-bit counter which uses the INTRC
source as the clock input. This yields an approximate
time interval of 2048 x 32 s = 65.6 ms. While the
PWRT is counting, the device is held in Reset.
The power-up time delay depends on the INTRC clock
and will vary from chip to chip due to temperature and
process variation. See DC parameter 33 for details.
FIGURE 5-3:
FIGURE 5-4:
DS39933D-page 56
INTERNAL RESET
INTERNAL RESET
PWRT TIME-OUT
PWRT TIME-OUT
INTERNAL POR
INTERNAL POR
Power-up Timer (PWRT)
MCLR
MCLR
V
V
DD
DD
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO V
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO V
T
PWRT
T
PWRT
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 5-3, Figure 5-4,
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
(Figure 5-5). This is useful for testing purposes or to
synchronize more than one PIC18FXXXX device
operating in parallel.
high
TIME-OUT SEQUENCE
and
will
Figure 5-6
begin
 2010 Microchip Technology Inc.
DD
, V
execution
DD
all
DD
RISE < T
): CASE 1
depict
immediately
PWRT
time-out
)