Cyclone V Device Handbook: Volume 2: Transceivers

ID 683586
Date 10/24/2018
Document Table of Contents Channel PLL as a CMU PLL

When you use the channel PLL as the CMU PLL, you can configure the transceiver channel only as a transmitter.

The CMU PLL operates in LTR mode only and supports the full range of data rates.

The VCO of the PLL operates at half rate and the L-counter dividers (PFD), after the VCO, extend the PLL data rate range.

Note: CDR functionality for the receiver is not available when you configure the channel PLL as a CMU PLL—you can use the transceiver channel only as a transmitter.
Figure 18. CMU PLL in Cyclone V Devices

The CMU PLL output serial clock, with a frequency that is half of the data rate, feeds the clock divider that resides in the transmitter of the same transceiver channel. The CMU PLLs in channels 1 and 4 feed the x1 and x6 clock lines.