The 8 pin Atmel AVRs have too few pins to use parallel communication during High-Voltage programming. They use serial communcation instead. This means that less signals have to be routed. HW setup for serial High-Voltage programming is:

  1. Switch power off

  2. Place the device to program in its socket according to the table in the High Voltage Programming section.

  3. Mount jumper OSCSEL on pin 1 and 2 to select SW controlled clock

  4. Mount jumper XTAL1 to route the oscillator signal to the device

  5. Mount jumpers VTARGET and RESET

  6. Use on 2-wire cable to connect the PB3 pin (pin 4) on the PORTB header to the XT1 pin (pin 7) on the PORTE / AUX header. This will connect the clock system to the AVR device.

  7. Use another 2-wire cable to connect the PB5 pin (pin 6) on the PORTB header to the RST pin (pin 4) on the PORTE / AUX header. This will connect the reset system to the AVR device.

  8. Use a third 2-wire cable to connect the PB0 and PB2 pins (pins 4 and 3) on the SPROG1 header to the DATA0 and DATA2 pins (pins 1 and 3) on the PROG DATA header.

  9. Use the last 2-wire cable to connect the PB1 pin (pin 1) on the SPROG1 header to the DATA1 pin (pin 2) on the PROG DATA header.

  10. Switch power on and you are ready to program

  11. Ensure that VTarget is between 4.5V and 5.5V before programming.

All connections are shown below.