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Shutdown Procedure

When the Propeller goes into Shutdown mode, the internal clock is stopped causing all cogs to halt and all I/O pins are set to input direction (high impedance).  Shutdown mode is triggered by one of the three following events:

  1. VDD falling below the brown-out threshold (≈2.7 VDC), when the brown-out circuit is enabled
  2. The RESn pin going low
  3. The application requesting a reboot

Shutdown mode is discontinued when the voltage level rises above the brown-out threshold and the RESn pin is high.

Tip:  In an application, when all cogs have completed their code execution and terminate, all I/O pins will again be set to input but the external clock (if used) and PLL circuitry (if used) is not stopped. If stopping the internal PLL and/or external clock is desired, the last operational cog can be programmed to shut them down. The internal clock is never stopped except during the Shutdown Procedure, above.

 

Propeller Help Version 1.1

Copyright © Parallax Inc.

5/13/2009