Parallel Port Programmer for AT89LP2052 and AT89LP4052

The design of the project utilizes the parallel programming mode through parallel port in order to create this 2052/4052 programmer.

For device programming, two interfaces with same command format are provided by the AT89LP2052/4052 microcontroller. One additional SS Signal for device programming is needed by the serial ISP Programming interface of the new 2052/4052. For IDE, the SPI signal will be added in the future to the existing AT89ISP cable and Software. The ISP fuse can only be re-enabled by parallel programming. To write the user fuses to disable the crystal oscillator bypass fuse, this programmer is also useful.

A 574 latch with 3 state outputs is used to connect the Dataport. The data are latched using the strobe signal of the parallel port. The lines with the host software are controlled by the Init signal of the parallel port. The HC273 device is used to control the CS signal and power supply signals of the microcontroller. The two LEDs on the programmer board display the status of Vcc and Vpp. The select_in signal from the parallel port pulses the microcontroller. The 12V programming voltage is generated by exyernal power supply.

Rest of the project