Visible to Intel only — GUID: mcn1430895861237
Ixiasoft
Visible to Intel only — GUID: mcn1430895861237
Ixiasoft
Design Example 1: I/O PLL Reconfiguration
The design example uses a 10AX115R2F40I2SGE2 device to demonstrate the implementation of the I/O PLL dynamic reconfiguration using the PLL Reconfig IP core. This design example consists of the IOPLL IP core, PLL Reconfig IP core, and In-System Sources & Probes Intel® FPGA IP core.
The I/O PLL synthesizes two output clocks of 400 MHz with 0 ps phase shift and 200 MHz with 0 ps phase shift on counter C0 output and counter C1 output respectively at medium bandwidth. The input reference clock is 50 MHz.
The PLL Reconfig IP core connects to a state machine to perform I/O PLL reconfiguration operation. A low pulse on the reset_SM input through the In-System Sources & Probes IP core triggers the I/O PLL reconfiguration operation. After I/O PLL reconfiguration operation is complete, the I/O PLL operates in the following configuration at medium bandwidth:
- 100 MHz with 0 ps phase shift on counter C0 output
- 100 MHz with 312 ps phase shift on counter C1 output
To run the test with the design example, perform these steps:
- Download and restore the an728-iopll-reconfig-general.qar file.
- If necessary, change the device and pin assignments (refclk, c0_out, c1_out, and locked pins) of the design example to match your hardware.
- Recompile the design example. Ensure that the design example does not contain any timing violation after recompilation.
- Open the AN.spf and program the device with test.sof.
- Assert a high pulse on reset_reconfig signal to reset the PLL Reconfig IP core. Then assert a high pulse on reset_SM signal to start the I/O PLL dynamic reconfiguration operation.