188.8.131.52. I/O Termination
|1||Check I/O termination and impedance matching for chosen I/O standards, especially for voltage-referenced standards.|
Voltage-referenced I/O standards require both an VREF and a termination voltage (VTT). The reference voltage of the receiving device tracks the termination voltage of the transmitting device. Each voltage-referenced I/O standard requires a unique termination setup.
Although single-ended, non-voltage-referenced I/O standards do not require termination, impedance matching is necessary to reduce reflections and improve signal integrity.
Intel® Agilex™ on-chip series and parallel termination provides the convenience of no external components. Alternatively, you can use external pull-up resistors to terminate the voltage-referenced I/O standards such as SSTL and HSTL.
Differential I/O standards typically require a termination resistor between the two signals at the receiver. The termination resistor must match the differential load impedance of the signal line. Intel® Agilex™ devices provide an optional on-chip differential resistor when using 1.5V True Differential Signaling.