Motorola IH5, MCPN750A manual Power-On Reset, Undervoltage Reset, Front Panel Push Button Reset

Memory Maps

**If the Chip Reset Bit is set to a 1, the bit will clear itself after the chip reset is complete.

Power-On Reset

The MCPN750A SBC generates a hard reset at power-on. During power up, reset is maintained for 140 to 560 milliseconds after the voltages have reached the minimum threshold.

Undervoltage Reset

The MCPN750A SBC generates a hard reset when the Hot Swap power control chip (LTC1643) detects a supply voltage +5V, +3.3V, +12V or - 12V fall below minimum thresholds of +4.75V, +3.135V, +10.8 and -10.8 volts respectively. The reset is maintained for 140 to 560 milliseconds after the voltages have returned to the minimum threshold. For undervoltage, the Vcc threshold to reset delay is typically 10 microseconds.

Front Panel Push Button Reset

The front panel RESET switch generates a hard reset when depressed for more than three (3) seconds. The reset is maintained as long as the switch is depressed.

CompactPCI Reset (RST#)

The CompactPCI reset signal RST# is monitored by the 21554 PCI-to-PCI bridge chip as the primary bus reset input. The bridge will generate a secondary bus reset that is used to generate a board hard reset.

Watchdog Timer Reset

Both the Raven ASIC Watchdog Timer 2 and the M48T559 watchdog timer may generate a hard reset when the associated timer expires, if this function is enabled.

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