PIC18C801-I/L Microchip Technology, PIC18C801-I/L Datasheet - Page 105

• Manufacturer Part Number: PIC18C801-I/L
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,84PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C801-I/L

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Type: ROMless
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 84-PLCC
• Processor Series: PIC18C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: 3-Wire, I2C, SPI, USART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 47
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: DV164005, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCXLT84L1 - SOCKET TRANSITION ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC18C801-I/LR; PIC18C801-I/LR; PIC18C801I/L

9.2
PORTB is an 8-bit wide, bi-directional port. The corre-
sponding data direction register is TRISB. Setting a
TRISB bit (= 1) will make the corresponding PORTB pin
an input (i.e., put the corresponding output driver in a
Hi-Impedance mode). Clearing a TRISB bit (= 0) will
make the corresponding PORTB pin an output ( i.e.,
put the contents of the output latch on the selected pin).
Read-modify-write operations on the LATB register
read and write the latched output value for PORTB.
EXAMPLE 9-2:
FIGURE 9-3:
CLRF
CLRF
MOVLW
MOVWF
Data Bus
WR LATB
or
WR PORTB
WR TRISB
RBPU
RBx/INTx
Set RBIF
2001 Microchip Technology Inc.
From other
RB7:RB4 pins
Note 1: I/O pins have diode protection to V
(2)
2: To enable weak pull-ups, set the appropriate TRIS bit(s)
PORTB, TRISB and LATB
Registers
and clear the RBPU bit (INTCON2 register).
PORTB
LATB
0CFh
TRISB
RD TRISB
RD LATB
RD PORTB
Data Latch
TRIS Latch
D
D
CK
CK
INITIALIZING PORTB
; Initialize PORTB by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
; Set RB3:RB0 as inputs
; RB5:RB4 as outputs
; RB7:RB6 as inputs
RB7:RB4 PINS BLOCK
DIAGRAM
Q
Q
Q
Q
Latch
EN
EN
D
DD
D
TTL
Input
Buffer
and V
RD PORTB
V
P
DD
SS
Advance Information
Weak
Pull-up
I/O pin
.
Buffer
Q1
Q3
ST
(1)
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is per-
formed by clearing bit RBPU (INTCON2 register). 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.
Pin RB3 is multiplexed with the CCP input/output. The
weak pull-up for RB3 is disabled when the RB3 pin is
configured as CCP pin. By disabling the weak pull-up
when pin is configured as CCP, allows the remaining
weak pull-up devices of PORTB to be used while the
CCP is being used.
Four of PORTB’s pins, RB7:RB4, have an interrupt-on-
change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e., any RB7:RB4 pin
configured as an output is excluded from the interrupt-
on-change comparison). The input pins (of RB7:RB4)
are compared with the old value latched on the last
read of PORTB. The “mismatch” outputs of RB7:RB4
are OR’d together to generate the RB Port Change
Interrupt with flag bit RBIF (INTCON register).
This interrupt can wake the device from SLEEP. The
user, in the Interrupt Service Routine, can clear the
interrupt in the following manner:
a)
b)
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.
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.
Any read or write of PORTB (except with the
MOVFF instruction). This will end the mismatch
condition.
Clear flag bit RBIF.
PIC18C601/801
DS39541A-page 105