FM3570MT20X

FM3570 CPU CONFIGURATION CONTROLLER Register/Multiplexer for Microprocessor VID Preliminary March 2001 FM3570 CPU CONFIGURATION CONTROLLER Register/Multiplexer for Microprocessor VID General Description The Fairchild FM3570 replaces the CPU motherboard’s configuration switches with an electronic implementation consisting of a 4/5-bit multiplexed, 1-bit latched port, standard 2-wire bus interface, and non-volatile latches. The FM3570 multiplexes the I-port input signals with two internal non-volatile registers that can be loaded through the serial port. The multiplexer is selected via the serial port and defaults to the I-port upon power-up. Pull-up resistors are provided on the input port to accommodate connections to open-drain outputs and to eliminate the need for external resistors. The device has opendrain outputs for easy interface to devices with different VDD levels. The serial port is an IIC compatible slave-only interface and supports both 100kbit and 400kbit modes of operation. The port is used to read the I-Port, write data to the internal non-volatile registers and select whether the I-port or one of the internal nonvolatile registers is output to the Y-port. The FM3570 is fabricated with advanced CMOS technology to achieve high density and low power operation. Features I Extended Operating Voltage Range 3.0V-5.5V I IIC Compatible Slave Interface. I ESD performance: Human body model > 2000V I Choice of 2.5V Outputs or Open-Drain Outputs Block Diagram Non_Mux_O...