The Atmel AT89C is a low-power, high-performance 8-bit microcontroller compatible with the MSC instruction set and object code. This report describes a construction analysis of the Atmel AT89C and the. AT89S 8-Bit Microcontrollers. Ten AT89C devices encapsulated in . The AT89CPU is a low voltage, high performance CMOS 8bit microcontroller in 20 pin DIP package. The device is manufactured using Atmel’s high.
|Published (Last):||14 February 2011|
|PDF File Size:||12.32 Mb|
|ePub File Size:||3.59 Mb|
|Price:||Free* [*Free Regsitration Required]|
The only disadvantage of this processor is a small and non-expandable program memory. If you need more exact specifications, download the original datasheet in.
For example, resident printing programs can do almost anything with the LPT. Using the Converter The converter interface is designed so that it can be used in any embedded application.
Thus, it is possible to port existing applications to an AT89C without change to the object code — as long as the software limits itself to the available hardware resources, including memory and ports.
The mode input to the converter determines what task the controller will perform when it is triggered.
Both software versions support so-called DEBUG mode, that should greatly simplify any troubleshooting. After the 8-bit data is shifted out, the controller program converts the serial port as an input shift register and reads back the converted ADC data microcontrloler 2 bytes.
I found I could modify an existing IntelHex loader program for the Basic system to get the required programmer code.
Optionally, set verification mode via bits P3. After the hex file is successfully received, the programmer proceeds with erasing the AT89C, then begins xt89c2051 it with the user object code.
Subsequently the system is loaded with the code in Listing One from within the terminal-emulator environment. This is possible because microcontroloer chip uses static memory. With 4 bits of mode input, up to 16 modes see Table 3 of operation can be implemented. Use as controllers in portable instruments is further simplified by at89cc2051 low power consumption and wide operating voltage range.
The amount of PEROM programmable and erasable read-only memory available on the AT89C is sufficient for most applications, including use in portable instruments, supervisory-control applications, autonomous robots, and more. The result of my design was a solution that offers a nibble wide input and output interface that, though tailored to connect to the PC parallel port, could be used anywhere else. It’s a pity it can’t run just with a RC-circuit for clock signal generating, and that an OTP version is not available.
As Table 1 shows, Port3 pins P3. The use of static memory allows the device to be operated at zero frequency. Port1 and Port3 are compatible to the P1 and P3 on an except Port1. Table 2 identifies the various modes for erasing, programming, and verifying the chip.
My objective was to build a simple programmer, that would be easy to make at home and would work without significant problems on the first try.
Consequently, I decided to microcntroller a simple programmer using circuits I had available. This is one of the simplest programmers. The AT89C can be programmed using a suitable programmer out of the target system.
After the code is burnt into the chip, the programmer power supply is turned off before removing the target chip. In the shift register microcoontroller, the TxD pin supplies the shift clock, and the RxD pin provides the data or reads the external data as per the direction.
A clear-status input that is used to erase previous status information. The target chip is then ready to be inserted into the wt89c2051 system. Increment address counter by pulsing XTAL1, set next instruction code via P1 Repeat steps 5 to 8 until the 2kB boundary is reached, or until the whole file has been programmed into the chip. At89f2051 circuit is intended for simple applications, where room and number of wires are limited. In some cases, it’s better to use a different design for the voltage switching part – see the end of this article.
You can view the modified schematics here. According to our measurements, power consumption averages approximately 12 mA.
The original design used the circuit; however, its use did not prove to be useful due to the parallel port output design see the article about LPT. Figure 6 shows the wiring scheme to connect the controller board to the PC printer adapter. The AT89C microcontroller can endure one thousand program and erase cycles.
A trigger input that triggers the converter into the requested mode. The only major inovation over standard series processors is the analog comparator on pins P1. Port1 output buffers have a 20 mA sink current capacity and can drive LEDs directly.
Low-power and power-down modes. Software is written in Pascal, the new version uses the Turbo Vision user interface.
The converter provides access to eight channels of bit ADC. Several people have independently pointed out that the voltage switches are not nicrocontroller in a totally “clean” way. While there are parallel output bit multichannel ADCs of similar performance, I decided to use available components to get the system working.
It also affords two software-selectable save-power modes. Port3 bits can also sink up to 20 mA of current, and when written with ones, can micrrocontroller used as inputs.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.