PIC18F45K20-I/ML Microchip Technology, PIC18F45K20-I/ML Datasheet - Page 65

• Manufacturer Part Number: PIC18F45K20-I/ML
• Description: IC PIC MCU FLASH 16KX16 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F45K20-I/ML

• Program Memory Type: FLASH
• Program Memory Size: 32KB (16K x 16)
• Package / Case: 44-QFN
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• 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 ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: CCP/ECCP/EUSART/I2C/MSSP/SPI
• Maximum Clock Frequency: 64 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 4
• 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: PG164130, DV164035, DV244005, DV164005, PG164120, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14-ch x 10-bit
• Package: 44QFN EP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 64 MHz
• Operating Supply Voltage: 2.5|3.3 V
• 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

3.11
© 2009 Microchip Technology Inc.
LESSON 11: PROGRAM MEMORY OPERATIONS
Topics covered in this include reading, writing and erasing locations in the Flash
program memory, protecting areas of program memory in the Configuration bits, and
considerations for using C pointers to program memory.
The MPLAB C Compiler simplifies working with data stored in program memory by
allowing pointers to program memory to be declared. The pointer address length is
either 16 or 24 bits, depending on which “Code Model” is selected in the project
settings. The “Small Code Model” will generate 16-bit pointers, while the “Large Code
Model” generates 24-bit pointers. For the best microcontroller performance, the “Small
Code Model” with 16-bit pointers should be used. The “Large Code Model” is
necessary for devices that have more than 64 KB of Flash program memory to be able
to point to locations above the first 64 KB of program memory. (The maximum of a
16-bit value is 65536, which is 64 x 1024 or 64K).
The Code Model settings may be changed in the MPLAB IDE by selecting Project >
Build Options… > Project. This brings up the Build Options dialog. Select the MPLAB
C18 tab and then “Memory Model” from the “Categories” drop-down box as shown in
Figure 3-52.
An individual pointer declaration may also use the keywords near or far to explicitly
specify the pointer address length. Use of either keyword overrides the code model
settings.
For more information on project memory models, see Chapter 3 of the “MPLAB C18 C
Compiler User’s Guide” (DS51288).
Key Concepts
near rom char *rom_pointer; // 16-bit pointer to program memory far
rom char *rom_pointer; // 24-bit pointer to program memory
- Pointers declared with the ROM keyword point to program memory loca-
- The EECON1 and EECON2 SFRs control program memory erase and write
- Unlike Data EEPROM memory, the Flash program memory must be explic-
- The CPx (code-protect) Configuration bits prevent programmers from read-
- The WRTx Configuration bits prevent software write operations on ranges of
- ROM pointers and reading Flash program memory
tions.
operations.
itly erased before it may be written.
ing ranges of a microcontroller’s program memory.
program memory, and the EBTRx bits prevent software read operations on
ranges of program memory.
PICkit™ 3 Debug Express Lessons
DS41370C-page 61