visisp52

Description: VisISP-52 is a Windows application compatible with all modern versions of Windows, including Win95, Win98, Win2000, WinME, and WinXP. It allows for the in-system programming of supported microcontrollers. Specifically designed to program the Atmel AT89S8252 and AT89S8253 installed in a Single Board Computer (SBC), it is also compatible with any design utilizing a similar In-System Programming (ISP) method and one of the supported microcontrollers. To install VisISP-52, download the installation program and execute it. This will install the application and create the necessary icons in the "Programs" menu for easy access. The interface of VisISP-52 is straightforward, featuring a single window with minimal menu options that provide access to its primary functions: writing new firmware to the microcontroller, reading the current firmware from the microcontroller, and erasing the microcontroller's memory. Before proceeding, ensure the correct microcontroller is selected from the "Microcontroller" drop-down menu. Currently, VisISP-52 only supports the Atmel AT89S8252 and AT89S8253.

To write firmware to the microcontroller, select the desired HEX file by pressing the "file" button next to the "File to Program" prompt. After selecting the file, download it to the microcontroller by pressing the "Write" button, during which a progress window will indicate the transfer status. To read the firmware from the microcontroller, press the "Read" button. This action will download the program memory from the microcontroller to the PC, prompting for a file name to save the data once the download is complete. Note that firmware download is not possible if the microcontroller has a security "lock bit" set. To erase the microcontroller, press the "Erase" button. The erase process is quick, followed by a verification phase where VisISP-52 reads the entire memory to confirm it has been erased. This verification can be canceled at any time without affecting the completion of the erase process.

The "Options" menu allows configuration of the ports (LPT port to which the SBC hardware is connected) and toggles the "Quick Program Mode," applicable only to the AT89S8252. When selected, this mode downloads only the bytes contained in the selected HEX file, leaving the remaining bytes unchanged. If not selected, the remaining memory will be filled with FFh data. Since the ISP circuit of the SBC was initially developed for the AT89S8252 and SP89, VisISP-52 is compatible only with ISP circuits following the original SP89 parallel port pin-out, which the SBC meets.

The D0 pin of the parallel port drives the SCK/P1.7 pin on the microcontroller, generating the SPI clock necessary for data transfer. The D1 pin of the parallel port controls the RST pin of the microcontroller, enabling reset mode, which is required for ISP when the reset is driven high. The D6 pin of the parallel port should drive a buffer IC to facilitate proper signal levels for ISP operations.

This application serves as a critical tool for developers and engineers working with the specified Atmel microcontrollers, providing essential capabilities for firmware management in embedded systems.VisISP-52 is a Windows application that will run on all modern versions of Windows (Win95, Win98, Win2000, WinME, and WinXP) and which will allow supported microcontrollers to be programmed "in-system". It was developed specifically to program the Atmel AT89S8252 and AT89S8253 installed in an SBC but should work equally well for any

other design that uses a compatible ISP and one of the supported microcontrollers. To install VisISP-52 on your computer, simply download the following installation program and run it. This will install the application on your computer and add the appropriate icons to your "Programs" menu.

You may then launch the program normally. VisISP-52`s interface is very straight-forward as is pictured below. A single window with minimal menu options provides access to the primary features of the program: Writing new firmware to the microcontroller, reading the firmware that is currently in the microcontroller, and erasing the microcontroller`s memory. Before proceeding, make sure you`ve selected the right microcontroller in the "Microcontroller" drop-down window.

At this time, VisISP-52 only supports the Atmel AT89S8252 and AT89S8253. To Write Firmware to the Microcontroller: In order to write firmware to the microcontroller, first select the HEX file you wish to download by pressing the "file" button to the right of the "File to Program" prompt. You will be allowed to select a HEX file which will be loaded into memory. Once you`ve selected the file, you may download it to the microcontroller by pressing the "Write" button.

A progress window will be displayed as the file is transferred to the microcontroller. To Read Firmware from the Microcontroller: You may read the contents of a microcontroller by pressing the "Read" button. This will download the program memory from the microcontroller to the PC. When the download is complete you will be prompted to enter a name for the HEX file that you wish to write the data to.

Note that you will not be able to download firmware if the microcontroller has a security "lock bit" set to prohibit such downloading. To Erase the Microcontroller: You may erase the microcontroller by pressing the "Erase" button. The erase process is very quick but is subsequently followed by a verification phase in which VisISP-52 will read the entire contents of the microcontroller`s memory to verify that it was, in fact, erased.

You may cancel this verification process at any time without affecting the erase process which is completed almost immediately. Options: The "Options" menu allows you to configure the ports (LPT port to which the SBC hardware is connected).

You may also toggle the "Quick Program Mode. " This option only applies to the AT89S8252. When the Quick Program Mode is selected, VisISP-52 will only download those bytes which are contained in the selected HEX file but will leave all other bytes alone. This means that if the HEX file only contains 2k of data, only 2k will be written to the AT89S8252 while the other 6k of the AT89S8252 will not be affected.

If this option is not selected then the remaining 6k will be filled with FFh data. Since the ISP circuit of the SBC was originally developed to operate with the AT89S8252 and SP89, VisISP-52 will only work with ISP circuits that are compatible with the original SP89 parallel port pin-out. The SBC meets this compatability requirement. SCK/P1. 7. The D0 pin of the parallel port drives the SCK/P1. 7 pin on the microcontroller. SCK is the SPI clock which is generated by VisISP-52 and allows the PC to clock data into and out of the microcontroller.

RST/pin 9. The D1 pin of the parallel port drives the RST pin of the microcontroller. This allows VisISP-52 to put the microcontroller into reset mode. This is necessary because ISP occurs with reset driven high. ISP Enable. The D6 pin of the parallel port should drive a buffer IC such as the 7