URSI - High Speed Reliable Connectivity¶
The Universal Responsive Serial Interface (URSI) is an innovative modulation scheme that delivers the highest effective transfer rate at lowest over-sampling clock for PLL-less CDR across asynchronous sub-systems, with adjustable jitter/clock tolerance for reliable transfers.
Features
- High Speed Asynchronous Single Wire or LVDS pair Serial Communication
- Lowest 3.5x Over-sampling PLL-less Decoder per bits to reach Gbps performance
- Adjustable Bandwidth to Rate ratio from 0.6 to 0.9
- Adjustable Jitter tolerance and clock mismatch ratio from ±10% to ±20%
- Responsive Interface with 3 bits of latency
- Lower Power: Inactive during Idle periods with Break signal
- Small footprint of about 12 macro-cells per encoder and Decoder
- Full Duplex or Half-Duplex with Bus Grant/Hold Signalization
- Optional Precision Nano-Clock Synchronization in DAQ systems
Long-Distance Applications
- Low-cost reliable communications up to 1 km @ 10 Mbps and more
- Low-cost DAQ Systems
- Sensors and Control in Building Automation
- Interface to Quartz-less Sensors: RC oscillator based sensor exposed to wide temperature stresses
- Robotics and Industry
Board Level, Short Distance, Applications
- Low Cost High-Speed Chip to Chip Communication: i.e. clock of 150 MHz yields effective rate of 43 Mbps
- Low Cost (SERDES-less) FPGA 150 Mbps Inter-connection
- Automotive replacement for low-cost LIN bus: removes clock alignment period
- Alternative Technology to 1-Wire and SPI
- Single wire opto-isolation reduces footprint and cost
- MCU single-pin tracing, communication, debugging
Comparison Table¶
Modulation | Max Speed | Signal Bandwidth | Clock/Data Recovery | Clock Tolerance | Idle to 1st Bit | Complexity / Cost |
---|---|---|---|---|---|---|
URSI | Gbps | >0.6 x rate | >3.5x Oversample | Typical ±20% | <3 bits | Low |
USB Full-speed | Mbps | 0.6 x rate | 4x Oversample | ±0.2% + Preamble | <10 bits | Medium |
Manchester | Gbps | 1.0 x rate | 5x Oversample, PLL | Preamble Sync | 2..64 bits | Low / Medium |
NRZI UART | Mbps | 0.6 x rate | 8..16x Oversample | ±2% | <3 bits | Low |
NRZI + 8b10, … | Gbps | 0.6 x rate | PLL CDR | Preamble Sync | <80 bits | Higher |