2.10 - SPC (or VSPC) [U6 Datasheet]

The SPC (possibly labeled VSPC on some older devices) terminal is used for manually resetting default values or jumping in/out of flash programming mode.

At power-up the device checks to see if SPC is shorted to the specified FIO terminal.  A jumper wire must be securely clamped between the terminals.

FIO0-SPC, Force to Normal Mode:  See LJSelfUpgrade.

FIO1-SPC, Force to Flash Mode:  See LJSelfUpgrade.

FIO2-SPC, Set-to-Factory:  To set the device to factory condition, power up with a jumper securely clamped from FIO2 to SPC, then remove the jumper and power cycle the device again.  The most common use of this it to disable the watchdog in the event it was enabled with a very short timeout and you are having trouble establishing communication with the device before the watchdog resets it.