Ultra Secure Four Channel (Port) I²C Interface

The DNR-I2C-534, DNF-I2C-534 and DNA-I2C-534 are four Port I²C (Inter-Integrated Circuit) interfaces designed for use with UEI’s popular RACKtangle, FlatRACK and Cube chassis respectively. They are fully supported by both PowerDNA (hosted) and UEIPAC (standalone/embedded) options of the chassis.

The I²C interface is compliant with UM10204 and supports Standard-Mode (100 kbit/s), Fast-Mode (400 kbit/s) and Fast-Mode+ (1Mbit/s), inputs and outputs are 3.3/5 V compatible and are brought out through a dSub 37 connector. The DNA-CBL-COM series brings the four I²C ports out to 9-pin dSub connectors.

Each of the four ports has both master and slave capability. The SCL and SDA pins include 1.5 kOhm pull up resistors to ensure reliable operation.

The standard I²C transaction includes sending a packet and then receiving an acknowledge. Failure to receive an ACK is an error condition. However, some I²C devices do not respond with an ACK. The DNx-I2C-534 can be set in a mode where it does not wait for an ACK, and does not generate an error message if the standard ACK is not received.

The board is part of UEI's popular Guardian series. The master of each port can be connected to the port's slave port via on-board switches. This allows the system to confirm the correct data has been sent out from each master.

To ensure data security and reliability from the host PC and/or embedded CPU, a CRC checksum is added to each I²C transaction written. This checksum remains with the data as it moves through the system and is checked by the DNx-I2C-534 FPGA prior to it being written to the output drivers. On data reads, the board’s FPGA adds a CRC checksum to the data and this is confirmed by the CPU prior to presenting the data to the application software. Note the FPGA is the last device in the data chain and reads and writes directly to the I²C receiver/transmitter chip.

The DNx-I2C-534 includes all software required for operation in both UEIPAC and PowerDNA chassis deployments. There are no licenses or royalty payments ever required and software revision updates are always available on the UEI web site at no charge. We offer SMBus hardware support, please call for software support.