PIC16LC924-08/CL View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16LC924-08/CL

8-Bit CMOS Microcontroller with LCD Driver

Microchip Technology 

5.3 PORTC and TRISC Register

PORTC is an 6-bit bi-directional port. Each pin is indi-

vidually configurable as an input or output through the

TRISC register. PORTC is multiplexed with several

peripheral functions (Table 5-5). PORTC pins have

Schmitt Trigger input buffers.

When enabling peripheral functions, care should be

taken in defining TRIS bits for each PORTC pin. Some

peripherals override the TRIS bit to make a pin an out-

put, while other peripherals override the TRIS bit to

make a pin an input. Since the TRIS bit override is in

effect while the peripheral is enabled, read-mod-

ify-write instructions (BSF, BCF, XORWF) with TRISC

as destination should be avoided. The user should refer

to the corresponding peripheral section for the correct

TRIS bit settings.

EXAMPLE 5-3: INITIALIZING PORTC

BCF

BCF

CLRF

BSF

MOVLW

MOVWF

STATUS,RP0 ; Select Bank0

STATUS,RP1

PORTC

; Initialize PORTC

STATUS,RP0 ;

0xCF

; Value used to

; initialize data

; direction

TRISC

; Set RC<3:0> as inputs

; RC<5:4> as outputs

; RC<7:6> always read 0

PIC16C9XX

FIGURE 5-5:

RBPU(2)

Data bus

WR Port

WR TRIS

PORTC BLOCK DIAGRAM

(PERIPHERAL OUTPUT

OVERRIDE)

VDD

Data Latch

DQ

P

weak

pull-up

CK

TRIS Latch

DQ

CK

TTL

Input

Buffer

I/O

pin(1)

RD TRIS

RD Port

QD

EN

RB0/INT

Schmitt Trigger

Buffer

RD Port

Note 1: I/O pins have diode protection to VDD and VSS.

2: To enable weak pull-ups, set the appropriate TRIS bit(s)

and clear the RBPU bit (OPTION<7>).

TABLE 5-5: PORTC FUNCTIONS

Name

RC0/T1OSO/T1CKI

RC1/T1OSI

RC2/CCP1

RC3/SCK/SCL

Bit# Buffer Type

bit0

ST

bit1

ST

bit2

ST

bit3

ST

RC4/SDI/SDA

bit4

ST

RC5/SDO

bit5

ST

Legend: ST = Schmitt Trigger input

Function

Input/output port pin or Timer1 oscillator output or Timer1 clock input

Input/output port pin or Timer1 oscillator input

Input/output port pin or Capture input/Compare output/PWM output

Input/output port pin or the synchronous serial clock for both SPI and

I2C modes.

Input/output port pin or the SPI Data In (SPI mode) or data I/O (I2C

mode).

Input/output port pin or Synchronous Serial Port data out

TABLE 5-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC

Address Name

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Value on

Power-on

Reset

Value on all

other resets

07h

PORTC

—

—

RC5 RC4 RC3 RC2 RC1 RC0 --xx xxxx --uu uuuu

87h

TRISC

—

— PORTC Data Direction Control Register

--11 1111 --11 1111

Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTC.

© 1997 Microchip Technology Inc.

DS30444E - page 35

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