Programming the AT89 LP2052/LP4052 Flash Memory, Lock Bits and User Fuses
The AT 89LP2052 / 89LP4052 microcontroller provide two interfaces with same command format for device programming. The serial ISP Programming interface of the new 2052/4052 microcontroller needs one additional SS Signal for device programming. This SPI signal will be added in the near future to the existing AT89ISP cable and Software (driver) for IDE. You can find more details in the Atmel specifications.
This 2052 / 4052 programmer design uses the parallel programming mode via Parallel Port. Only parallel programming can re-enable the ISP Fuse. This programmer is also usefull if you need to write the user fuses to disable the XTAL Osc Bypass fuse – e.g. to test the LP2052 in existing 2051 hardware designs.
The Dataport is connected via a 574 latch with 3 State outputs. The strobe signal of the Parallel Port is used to latch the datas. The CS/ Signal and Powersupply signals Vcc/Vpp of the micro are controlled through the HC273 device. The Init signal of the parallel Port is used to control these lines with the host software. The status of Vcc and Vpp are displayed with two LEDs on the programmer board. An external Oscillator is not required. The Atmel microcontroller is pulsed with the Select_In signal from the parallel port.
An external power supply (16V= ) is needed to generate the 12V programming voltage.
Visit www.atmel.com to find an application note how to use the Parallel Port for existing Atmel AT89 C/LV 51/52 devices.
Data polling is currently not supported to reduce the number of components on the board. To verify the datas we still have to test the SPI interface via parallel Port.
To minimize the influence of undefined states it is necessary to start the host software (to disable Vcc and Vpp !) before a 2052 / 4052 LP device is put into the socket.
For more detail: AT89LP2052 / AT89LP4052 Parallel Port Programmer