
Freescale Semiconductor
Dual DBUS Master with Differential Drive and Frequency Spreading
The 33780 is a master device for two differential DBUS buses. It contains the logic to interface the buses to a standard serial peripheral interface (SPI) port and the analog circuitry to drive data and power over the bus as well as receive data from the remote slave devices.
The differential mode of the 33780 generates lower electromagnetic interference (EMI) in situations where data rates and wiring make this a problem. Frequency spreading further reduces interference by spreading the energy across many channels, reducing the energy in any single channel.
FEATUREs
• Two Independent DBUS I/Os
• Common SPI Interface for All Operations
• Open-Drain Interrupt Output with Pull-up
• Maskable Interrupts for Send and Receive Data Status
• Automatic Message Cyclical Redundancy Checking (CRC) Generation and Checking
• Four-Stage Transmit and Receive Buffers
• 8- to 16-Bit Messages with 0- to 8-Bit CRC
• Independent Frequency Spreading for Each Channel
• Pb-Free Packaging Designated by Suffix Code EG