Document
FM3540/60 4/5 Bit Multiplexed, 1 Bit Latched Port with Standard 2-Wire Bus Interface and Non-Volatile Latches
October 2001
FM3540/60 4/5 Bit Multiplexed, 1 Bit Latched Port with Standard 2-Wire Bus Interface and Non-Volatile Latches
General Description
The FM3540/60 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 supports a choice of either 2.5V output or Open Drain Outputs for easy interface to devices with different VDD Levels. The serial port is an IIC compatible slave only interface and supports both 100kbits and 400kbits 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 FM3540/60 is fabricated with an advanced CMOS technology to achieve high density and low power.
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_Out
I[4:0]
Y[4:0] Mux1 SOPRA Mux2 SOPRB
MXSB, MXSA
IIC Read Logic
Mux3 Control Logic
MUXSEL OVRD
SDA SCL
IIC Interface
Shift Register
Slave Address Register ASEL Comparator
Start/Stop Logic
© 2001 Fairchild Semiconductor Corporation FM3540/60 Rev. C
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www.fairchildsemi.com
FM3540/60 4/5 Bit Multiplexed, 1 Bit Latched Port with Standard 2-Wire Bus Interface and Non-Volatile Latches
Ordering Information
Order Number
FM3540CM14 FM3540CMT14 FM3540SM14 FM3540SMT14 FM3560M20 FM3560MT20
Note About Y-Port Output Type: FM3560 device has a dedicated input pin (LEVEL) to select either "Fixed 2.5Volts" or "Open-Collector" Y-Port output type. Note About Device Address: 1. For FM3540 with an alternate device address of 0110111, contact Fairchild Marketing/Sales. 2. FM3560 device has a dedicated input pin (ASEL) to select either "1001110" or 0110111" as device address.
Package Number
M14A MTC14 M14A MTC14 M20B MTC20
Package Description
14-Pin SO 14-Pin TSSOP 14-Pin SO 14-Pin TSSOP 20-Pin SO 20-Pin TSSOP
Packing
T&R T&R T&R T&R T&R T&R
Y-Port Output Type
Open-Collector Open-Collector Fixed 2.5V Fixed 2.5V (See Note below) (See Note below)
Device Address
1001110 1001110 1001110 1001110 (See Note below) (See Note below)
Pin Connection Diagrams
14-Pin Packages FM3540
SDA I0 I1 I2 I3 I4 GND 1 2 3 4 5 6 7 14 13 12 11 10 9 8 SCL VCC Y0 Y1 Y2 Y3 Y4
20-Pin Packages FM3560
SCL SDA OVRD I0 I1 I2 I3 I4 Level GND 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 VCC ASEL WP Non_Mux_Out MUXSEL Y0 Y1 Y2 Y3 Y4
Pin Description
Pin Name
I[0:4] Y[0:4] SCL Override# WP Non_Mux_Out Mux_Sel Level ASEL SDA
Description
Data Inputs w/Pullups (10K-40K) O/D Data Outputs Serial Port Clock Input (120K pullup) Override Input, sets all outputs to 0 Write Protect Input Non-Multiplexed Output Mux. Select Input Level Select Input Address Select Input Serial Port Data I/O (120K pullup)
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FM3540/60 Rev. C
www.fairchildsemi.com
FM3540/60 4/5 Bit Multiplexed, 1 Bit Latched Port with Standard 2-Wire Bus Interface and Non-Volatile Latches
Functional Description
The FM3540/60 has two primary functional modes of operation and an additional mode for programming the device. Operational Modes During standard operation the device will either pass an address to the Y-Port from the I-Port or from an internally programmed value. At power up the device will default to passing the I-Port value to the Y-Port. The I-port values are generated from the motherboard of the system and may be hardwired or driven by another device. Pullup resistors are provided on the device to accommodate this device being driven by open drain output drivers. The device expects standard CMOS input signals. The level of the output signal is determined by the Level input. If this input is connected to Vss/Ground, the output is at 2.5V on the multiplexed outputs (Y0-Y4). The non-multiplexed output is always at CMOS levels. The Level input, if left unconnected (it has an internal pullup), will cause the Y0-Y4 outputs to operate as open-drain outputs. The override# input, when set to 0, will cause all the outputs to be set to 0. The WP signal, if set to logic 1, will prevent data from being written to the non-volatile register. The mux_sel input, when set to logic 0, will select the data from the non-volatile register to drive on the Y0-4 outputs. If set to logic 1, the data from the inputs are selected instead. The non_mux_out latch is transparent when the mux_sel signal is at logic 0, and will latch data when the mux_select is in a logic 1 state.
Serial Output Port Register (SOPR)
(Address 000b and 001b) MXSB MXSA 0 b7 0 b6 I5 b5.