435303149-PIC-ppt microcontroller introduct
- 1. PIC Microcontroller • PIC microcontroller was developed in the year 1993 by microchip technology. • The term PIC stands for Peripheral Interface Controller. Initially this was developed for supporting PDP(programmed data processor) computers to control its peripheral devices, and therefore, named as a peripheral interface device.
- 2. Features of the PIC18 microcontroller • - 8-bit CPU • - 2 MB program memory space • - 256 bytes to 1KB of data EEPROM • - Up to 3968 bytes of on-chip SRAM • - 4 KB to 128KB flash program memory • - Sophisticated timer functions that include: input capture, output compare, • PWM, real-time interrupt, and watchdog timer • - Serial communication interfaces: SCI, SPI, I2C, and CAN • - Background debug mode (BDM) • - 10-bit A/D converter • - Memory protection capability • - Instruction pipelining • - Operates at up to 40 MHz crystal oscillator
- 3. Architecture of PIC Microcontroller
- 4. Microprocessor Unit • Includes Arithmetic Logic Unit (ALU), Registers, and Control Unit – Arithmetic Logic Unit (ALU) • Instruction decoder – 16-bit instructions • Status register that stores flags – 5-bits • WREG – working register – 8-bit accumulator
- 5. Microprocessor Unit – Registers • Program Counter (PC) – 21-bit register that holds the Program Memory address • Bank Select Register (BSR) – 4-bit register used in direct addressing the Data Memory • File Select Registers (FSRs) – 12-bit registers used as memory pointers in indirect addressing Data Memory – Control unit • Provides timing and control signals – Read and Write operations
- 6. PIC18F - Address Buses • Address bus – 21-bit address bus for Program Memory • Addressing capacity: 2 MB – 12-bit address bus for Data Memory • Addressing capacity: 4 KB
- 7. Data Bus and Control Signals • Data bus – 16-bit instruction/data bus for Program Memory – 8-bit data bus for Data Memory • Control signals – Read and Write
- 8. PIC18F – MPU and Memory
- 10. PROGRAM COUNTER AND ROM MEMORY SPACE
- 12. The PIC18 Memory Organization • Data Memory and Program Memory are separated • - Separation of data memory and program memory makes possible the simultaneous access of data and instruction. • - Data memory are used as general-purpose registers or special function registers • - On-chip Data EEPROM are provided in some PIC18 MCUs
- 13. 1. PIC18F452/4520 Memory • Program Memory: 32 K – Address range: 000000 to 007FFFH • Data Memory: 4 K – Address range: 000 to FFFH • Data EEPROM – Not part of the data memory space – Addressed through special function registers
- 14. 2. Data Memory Banks/BSR SELECTION
- 15. PIC18 I/O Ports • Five I/O ports – PORT A through PORT E – Most I/O pins are multiplexed – Generally have eight I/O pins – Addresses already assigned to these ports – Each port is identified by its assigned SFR
- 16. PIC18 I/O Ports • The series of PIC16 consists of five ports such as Port A, Port B, Port C, Port D & Port E. • Port A is an 16-bit port that can be used as input or output port based on the status of the TRISA (Tradoc Intelligence Support Activity) register. • Port B is an 8- bit port that can be used as both input and output port. • Port C is an 8-bit and the input of output operation is decided by the status of the TRISC register. • Port D is an 8-bit port acts as a slave port for connection to the microprocessor BUS. • Port E is a 3-bit port which serves the additional function of the control signals to the analog to digital converter
- 17. Diagram of I/O Ports
- 20. Feature of Timer 0 • 8-bit timer/counter • Readable and writable • 8-bit software programmable prescaler • Internal (4 Mhz) or external clock select • Interrupt on overflow from FFh to 00h • Edge select (rising or falling) for external clock
- 22. Timer 1 Timer 1 (TMR1) 16-bit timer/counter overflow occurs, an interrupt is generated TMR1 module can operate in 2 basic modes- (i). a timer (ii).a counter TMR1 increments from 0000h to FFFFh and rolls over to 000h TMR1 operating mode is determined by the clock select bit, TMR1CS R.Hariharan AP / EEE - SECE
- 23. R.Hariharan AP / EEE - SECE
- 24. Example
- 25. Timer 2 Timer 2 (TMR2) 8-bit timer with Prescaler and Postscaler TMR2 can be used as – PWM TMR2 register is R/W – cleared on any device reset. Timer2 module has an 8-bit period register PR2 Timer2 increments from 00h till reaches PR2 PR2 is initialized to FFh upon reset. R.Hariharan AP / EEE - SECE
- 26. R.Hariharan AP / EEE - SECE
- 27. Interrupts Polling Interrupts External System Software Interrupt Hardware Interrupt Request from software Request from external Hardware device R.Hariharan AP / EEE - SECE
- 28. PIC16C7X family has up to 12 sources of interrupt External • Timer 0 • Timer 1 • RB Port Change • Parallel Slave Port Read/Write • A/D Converter • USART Receive • USART Transmit • Synchronous Serial Port • CCP1 (Capture, Compare, PWM) • CCP2 (Capture, Compare, PWM) • TMR2 to PR2 Match R.Hariharan AP / EEE - SECE