T4 Maximum tUSER for SPI Active and Passive Modes
The following waveform illustrates the minimum and maximum values for tUSER.
- Point A—User-defined trigger point to start counter on tUSER
- Point B—VIH (with Schmitt Trigger) of Trion I/Os
The maximum tUSER value can be derived based on the following formula:
| Configuration Setup | tUSER Maximum |
|---|---|
| Single Trion FPGA | tUSER = t(from A to B) + tUSER_MIN |
| Slave FPGA in a dual-Trion FPGA SPI chain | |
| Master FPGA in a dual-Trion FPGA SPI chain | tUSER = (1344 / SPI_WIDTH) * CCK period + tUSER_MIN + t(from A to B) |