Atmega32A ISP Programmer

                       There are a large variety of Programmers for the AVR's. Among those In-system Programmers are most versatile and easy to use. The Manufacturer Website itself provides different kinds of development kits, Programmers, Debuggers, Emulators, JTAG devices and different addons for the application development using AVR microcontrollers.Also the software tools for programming, simulating the results are also provided. The complete tool set called the AVR studio can be downloaded for free by signing in as a user. The only reason for not using these standard devices(Programmers, debuggers etc. provided by the manufacturers ), is their cost and non availability in certain areas.

                    This lead to development of new 3rd party programmers which are simple and easy to use. They can just be plugged into one of the ports available on the PC, configured properly with the software can work fine. The best option is to use one of these Programmers. One such is provided at lancos.com. PonyProg is a hex file burner software which works in conjunction with SI-Prog, the ISP, different for different family of Microcontrollers. 

AVR - In System Programming

                         Almost all the AVR's support the ISP programming. ISP stands for In-system Programming which means that these microcontrollers can be programmed while they are with in the end circuit. This reduces cost and time for programming and also reduces the programming difficulty. In-System Programming allows programming and reprogramming of any AVR microcontroller positioned inside the end system. Using a simple Three-wire SPI interface, the In-System Programmer communicates serially with the AVR microcontroller, reprogramming all non-volatile memories on the chip.The info about the ISP programming is provided in the AVR doc0943.

                          

              For In-System Programming, the programmer is connected to the target using as few wires as possible. To program any AVR microcontroller in any target system, a simple Six-wire interface is used to connect the programmer to the target PCB.The Serial Peripheral Interface (SPI) consists of three wires: Serial ClocK (SCK), 

Master In – Slave Out (MISO) and 

Master Out – Slave In (MOSI). 

                In In-System Programming the programmer always operate as the Master, and the target system always operate as the Slave. The In-System Programmer (Master) provides the clock for the communication on the SCK Line. Each pulse on the SCK Line transfers one bit from the Programmer (Master) to the Target (Slave) on the Master Out – Slave In (MOSI) line. Simultaneously, each pulse on the SCK Line transfers one bit from the target (Slave) to the Programmer (Master) on the Master In – Slave Out (MISO) line.

AVR - Programming methods

There are many ways of programming the AVR family of Microcontrollers and these ways are described in this post of AVR Freaks.Thanks to Mr.abcminiuser for this post.The different methods are as follows.

METHOD 1: In System Programming (ISP)
Supported By: Vast majority of AVRs (see below posts)
Supported Programmers: AVRISP MKI/II, JTAG MKII, STK500, STK600, Dragon, AVRISP clones, AVR910 Programmers, AVRONE

In System Programming is perhaps the most common method of programming the flash, EEPROM, fuse and lockbytes of the entire AVR line. ISP can program AVRs at extremely high clock rates (assuming the target AVR is running at a high frequency and the programmer supports it) and is the method of choice for almost all AVR hobbyists. There are many, many AVRISP clones and AVR910 programmers on the market in addition to simple do-it-yourself dongles which connect to your computer's parallel port.

Recent new dongle designs may use the computer's serial port, however anecdotal evidence has said that this method is *extremely* slow due to technical limitations.

ISP requires that the target AVR is running at a clock rate of at least four times that of the ISP clock. This is a common pitfall and a source of confusion to many new to AVRs.

METHOD 2: JTAG
Supported By: See AVRStudio Tools help for MKI and MKII device support
Supported Programmers: JTAG-ICE, JTAG-ICE MKII, Dragon, JTAG-ICE clones, AVRONE, STK600 (programming only)

Technically JTAG is a debugging system, not a programming method. Still, the JTAG interface allows for the programming of an AVR which supports it.