PIC18F45K20-E/ML Microchip Technology, PIC18F45K20-E/ML Datasheet - Page 33

• Manufacturer Part Number: PIC18F45K20-E/ML
• Description: 32KB, Flash, 1536bytes-RAM, 36I/O, 8-bit Family,nanowatt XLP 44 QFN 8x8x0.9mm TU
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F45K20-E/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 44-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: DM240313 - BOARD DEMO 8BIT XLPAC164112 - VOLTAGE LIMITER MPLAB ICD2 VPPDM164124 - KIT STARTER FOR PIC18F4XK20AC164322 - MODULE SOCKET MPLAB PM3 28/44QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.4
© 2009 Microchip Technology Inc.
LESSON 4: SWITCH INPUT
The demo board switch is used in the lesson to rotate the LEDs once on each press.
3.4.1
This lesson has added a header file to the project named 04 Switch Input.h
as shown in Figure 3-20.
FIGURE 3-20:
While it is assumed that the reader is familiar with C language header files, we’ll note
that in the 04 Switch Input.h header file the #define directive has been used to
give more meaningful names to the switch I/O pin variable and a constant value.
As with other C compilers use of #define, MPLAB C will replace all instances of the
text “Switch_Pin” with the text “PORTBbits.RB0” at compile time. Remember, for the
compiler to know about the #define definitions, the header file must be included in
the C file, as is done in 04 Switch Input.c:
Key Concepts
- The directive #define can be used to give SFR registers and bits more
- I/O pins that share an analog input channel must be configured as digital
- The PORTx SFRs are used to read the logic state on an input port pin.
- Mechanical switch debouncing can be handled in software to eliminate
meaningful names.
pins if used as digital inputs using SFR ADCON1, or they will always read
‘0’.
external components that may be otherwise required.
#define
#define
#include
Files and the #define Directive
PICkit™ 3 Debug Express Lessons
HEADER FILE
Switch_Pin
DetectsInARow
"04
Switch
Input.h"
PORTBbits.RB0
5
//
header file
DS41370C-page 29