AT89LP2052 / AT89LP4052 Parallel Port Programmer 

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.

Programmer Hardware
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 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.

Programmer Software
The programmer is controlled by software running on the host. The software supports writing the flash memory (bin and hex files), Lock bits and user fuses in parallel programming mode. The software can handle the Vcc and Vpp signals of the microcontroller. The status of the signals are displayed by LED 1 and LED 2 on the board.

The programming algorithm is easy. You can can find detailed descriptions in the Atmel specs.

Some VB software parts (not complete):

Private Sub device_program_enable()
 'Program enable sequence
 DataWrite_Enable (True)  ' enable 574 on Board
 P32_CS_Signal (False)    ' P3.2 CS to low
 datasend (&HAA)             ' send preamble
 datasend (&HAC)             ' send opcode
 datasend (&H53)              ' send AdressHigh to enable
 P32_CS_Signal (True)      ' P3.2 CS to high
 DataWrite_Enable (False) ' tristate 574 on Board

End Sub

Private Sub datasend(data As Byte)
  ' send datas to micro, clocks 574 and clocks P_SelectIn
  Out PortAddress, data      ' send preamble
  cr_strobe (cr_DataStrobe) ' P strobe for latch to 572
  cr_strobe (cr_clkstrobe)    ' SelectIn: strobe for 2052/4052 XTAL1
End Sub

Public Sub P32_CS_Signal(stat As Boolean)
 ' true means that signal on Board is high (= VCC =deactivated) 

  HC_Reg = HC_Reg Xor 2 ^ P32_CS ' toggle CS signal
  Out PortAddress, HC_Reg              ' Daten anlegen
  cr_strobe (cr_InitStrobe)                  ' init strobe for 74HC273 Bit 0
End Sub

Questions ? Schaltplan und Layout im Eagle Format ?
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