Watchdog timer in pic microcontroller pdf

Please forward this error screen to 69. Book Introduction: John Morton offers a uniquely concise and practical guide to getting up and running with the PIC Microcontroller. The PIC is one of the most popular of the microcontrollers that are transforming electronic project work and product design, and this book is the ideal introduction for students, teachers, technicians and electronics enthusiasts. Assuming no prior knowledge of microcontrollers and watchdog timer in pic microcontroller pdf the PIC Microcontroller’s capabilities through simple projects, this book is ideal for electronics hobbyists, students, school pupils and technicians.

The revised third edition focuses entirely on the re-programmable flash PIC microcontrollers such as the PIC16F54, PIC16F84 and the extraordinary 8-pin PIC12F508 and PIC12F675 devices. Simple programs and circuits introduce key features and commands through project work. Table of Contents provided by Ingram. EPROM for program storage, some with provision for erasing memory. All current models use flash memory for program storage, and newer models allow the PIC to reprogram itself. Program memory and data memory are separated. Data memory is 8-bit, 16-bit, and, in latest models, 32-bit wide.

Third party and some open-source tools are also available. PIC devices are popular with both industrial developers and hobbyists due to their low cost, wide availability, large user base, extensive collection of application notes, availability of low cost or free development tools, serial programming, and re-programmable Flash-memory capability. The PIC used simple microcode stored in ROM to perform its tasks, and although the term RISC was not used at the time, it shares some common features with RISC designs. In 1985, General Instrument sold their microelectronics division and the new owners cancelled almost everything which by this time was mostly out-of-date. The PIC, however, was upgraded with an internal EPROM to produce a programmable channel controller.

In 2001, Microchip introduced Flash programmable devices, with full production commencing in 2002. PIC and PICmicro are registered trademarks of Microchip Technology. It is generally thought that PIC stands for Peripheral Interface Controller, although General Instruments’ original acronym for the initial PIC1640 and PIC1650 devices was “Programmable Interface Controller”. The acronym was quickly replaced with “Programmable Intelligent Computer”. 1993, was the first Microchip CPU with on-chip EEPROM memory. By 2013, Microchip was shipping over one billion PIC microcontrollers every year.

PIC micro chips are designed with a Harvard architecture, and are offered in various device families. The baseline and mid-range families use 8-bit wide data memory, and the high-end families use 16-bit data memory. The latest series, PIC32MZ is a 32-bit MIPS-based microcontroller. The program memory of “C” devices is variously described as OTP, ROM, or EEPROM. As of October 2016, the only OTP product classified as “In production” is the pic16HV540.

These devices feature a 12-bit wide code memory, a 32-byte register file, and a tiny two level deep call stack. They are represented by the PIC10 series, as well as by some PIC12 and PIC16 devices. Baseline devices are available in 6-pin to 40-pin packages. Generally the first 7 to 9 bytes of the register file are special-purpose registers, and the remaining bytes are general purpose RAM. If banked RAM is implemented, the bank number is selected by the high 3 bits of the FSR.

Note that a CALL instruction only includes 8 bits of address, and may only specify addresses in the first half of each 512-word page. There are some “enhanced baseline” variants with interrupt support and a four-level call stack. PIC10F32x devices feature a mid-range 14-bit wide code memory of 256 or 512 words, a 64-byte SRAM register file, and an 8-level deep hardware stack. A complex set of interrupts are available. These devices feature a 14-bit wide code memory, and an improved 8-level deep call stack. The instruction set differs very little from the baseline devices, but the two additional opcode bits allow 128 registers and 2048 words of code to be directly addressed. There are a few additional miscellaneous instructions, and two additional 8-bit literal instructions, add and subtract.

The mid-range core is available in the majority of devices labeled PIC12 and PIC16. 96 bytes are used for general-purpose RAM. STATUS register which holds the RAM bank select bits. The PCLATH register supplies high-order instruction address bits when the 8 bits supplied by a write to the PCL register, or the 11 bits supplied by a GOTO or CALL instruction, is not sufficient to address the available ROM space. The 17 series is not recommended for new designs, and availability may be limited to users.

PIC17 devices were produced in packages from 40 to 68 pins. In 2000, Microchip introduced the PIC18 architecture. Unlike the 17 series, it has proven to be very popular, with a large number of device variants presently in manufacture. In contrast to earlier devices, which were more often than not programmed in assembly, C has become the predominant development language.