MA180025 Microchip Technology, MA180025 Datasheet - Page 120

• 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

corresponding Data Direction and Output Latch registers
PIC18F87J90 FAMILY
10.3
PORTB is an 8-bit wide, bidirectional port. The
are TRISB and LATB. All pins on PORTB are digital only
and tolerate voltages up to 5.5V.
EXAMPLE 10-2:
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is
performed by clearing bit, RBPU (INTCON2<7>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on a Power-on Reset.
DS39933D-page 120
CLRF
CLRF
MOVLW
MOVWF
PORTB, TRISB and
LATB Registers
PORTB
LATB
0CFh
TRISB
; Initialize PORTB by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
; Set RB<3:0> as inputs
; RB<5:4> as outputs
; RB<7:6> as inputs
INITIALIZING PORTB
Four of the PORTB pins (RB<7:4>) have an
interrupt-on-change feature. Only pins configured as
inputs can cause this interrupt to occur (i.e., any
RB<7:4> pin configured as an output is excluded from
the interrupt-on-change comparison). The input pins (of
RB<7:4>) are compared with the old value latched on
the last read of PORTB. The “mismatch” outputs of
RB<7:4> are ORed together to generate the RB Port
Change Interrupt with Flag bit, RBIF (INTCON<0>).
This
power-managed modes. The user, in the Interrupt
Service Routine, can clear the interrupt in the following
manner:
a)
b)
c)
A mismatch condition will continue to set flag bit, RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit, RBIF, to be cleared after one T
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt-on-change
feature. Polling of PORTB is not recommended while
using the interrupt-on-change feature.
RB<3:2> are multiplexed as CTMU edge inputs.
RB<5:0> are also multiplexed with LCD segment
drives, controlled by bits in the LCDSE1 and LCDSE3
registers. I/O port functionality is only available when
the LCD segments are disabled.
Any read or write of PORTB (except with the
MOVFF (ANY), PORTB instruction). This will end
the mismatch condition.
Wait one instruction cycle (such as executing a
NOP instruction).
Clear flag bit, RBIF.
interrupt
can
 2010 Microchip Technology Inc.
wake
the
device
CY
delay.
from