ADLINK Technology cPCI-3920 Series User Manual

Contents

ADLINK Technology cPCI-3920 Series User Manual Manual pdf 40 page image

30 Functional DescriptionA reset will be generated by the following conditions:X +5 V supply falls below 4.1 V (typ.)X +3.3 V supply falls below 2.93 V (typ.)X Pushbutton ´RESET" pressed (only on 8HP)X Watchdog overflowX CompactPCI backplane PRST# input (CompactPCI con-nector J2, pin C17)SMBus DevicesThe cPCI-3920 provides a System Management Bus (SMBus)for access to several system monitoring and configurationfunctions. The SMBus consists of a two-wire I2C bus interface.The following table describes the function and address of everyonboard SMBus device.Table 3-2: SMBus Devices and AddressesThermal Management/ System MonitoringThe IICH can be used to monitor several critical hardware param-eters of the system, including power supply voltages, fan speedsand temperatures, all of which are very important for the properoperation and stability of a high-end computer system. The IICHprovides an LPC bus interface.The voltages +12 V, +5 V, +3.3 V, +2.5 V, and Vcore are super-vised. One fan tachometer output can be measured using theIICH’s FAN1 input. One pulse width modulation (PWM1) outputcan be used for FAN speed control.The temperature sensors on the IICH monitor the CPU tempera-ture and the ambient temperature around the IICH to ensure thatthe system is operating at a safe temperature level. If the CPUDevice SMBUS AddressClock Buffer DChClock Generator D2hSPD A0hEEPROM (Board VPD) AEh