8XC196MC, MD, MH USER’S MANUAL

16.7.2 Power-up and Power-down Sequences

When you are ready to begin programming, follow these power-up and power-down procedures.

WARNING

Failure to observe these warnings will cause permanent device damage.

Voltage must not be applied to VPP while VCC is low.

The VPP voltage must be within 1 volt of VCC while VCC is less than 4.5 volts. VPP must not go above 4.5 volts until VCC is at least 4.5 volts.

The VPP maximum voltage must not be exceeded.

EA# must reach programming voltage before VPP does so.

The PMODE pins (P0.7:4) must be in their desired states before RESET# rises.

All voltages must be within the ranges specified in the datasheet and the oscillator must be stable before RESET# rises.

The power supplies to the VCC, VPP, EA# and RESET# pins must be well regulated and free of glitches and spikes.

All VSS pins must be well grounded.

16.7.2.1Power-up Sequence

1.Hold RESET# low while VCC stabilizes. Allow VPP and EA# to float during this time.

2.After VCC and the oscillator stabilize, continue to hold RESET# low and apply VPP voltage to EA#.

3.After EA# stabilizes, apply VPP voltage (+12.5V) to the VPP pin.

4.Set the PMODE value to select a programming algorithm.

5.Bring the RESET# pin high.

6.Complete the selected programming algorithm.

16.7.2.2Power-down Sequence

1.Assert the RESET# signal and hold it low throughout the powerdown sequence.

2.Remove the VPP voltage from the VPP pin and allow the pin to float.

3.Remove the VPP voltage from the EA# pin and allow the pin to float.

4.Turn off the VCC supply and allow time for it to reach 0 volts.

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Intel 8XC196MH, 8XC196MD, 8XC196MC manual Power-up and Power-down Sequences, Power-up Sequence