Power-On And Reset; Kcu105 On-Board Clocks; Clock Menu - Xilinx KCU105 User Manual

Power-On and Reset

Prior to displaying the main menu, the system controller initializes the adjustable voltage
(VADJ) on the FPGA FMC expansion port interface within the available choices of 1.8V, 1.5V,
1.2V, and 0.0V.
• If no cards are attached to the FMC ports, the VADJ voltage is set to 1.8V.
• When one FMC card is attached, its I2C EEPROM is read to find a VADJ voltage
supported by both the KCU105 board and the FMC module within the available choices
of 1.8V, 1.5V, 1.2V, and 0.0V.
• When two FMC cards are attached with differing VADJ requirements, VADJ is set to the
lowest value compatible with the KCU105 board and the FMC modules, within the
available choices of 1.8V, 1.5V, 1.2V, and 0.0V.
The VADJ voltage is set and then the main menu is displayed. The VADJ settings can be
viewed by scrolling back through the terminal window output.
If an attached FMC card does not have its I2C EEPROM programmed, the firmware sets
IMPORTANT:
VADJ to 0.0V.
The VADJ voltage can be set manually with the FMC menu.

KCU105 On-board Clocks

The KCU105 board hosts two programmable clocks. One is the user programmable system
clock (Silicon Labs Si570) that operates in the frequency range between 10 MHz and
810 MHz. The second KCU105 programmable clock source is the Silicon Labs Si5328B,
which is typically used as a jitter attenuator for a recovered clock from a serial transceiver.
However, the Si5328B can also be used as an independent clock source with a frequency
range of 8 kHz to 808 MHz. In addition to the programmable clock sources, the UltraScale
FPGA evaluation boards provide a 300 MHz fixed frequency system clock.

Clock Menu

The clock menu is used to set the frequency of the onboard programmable clock sources. At
KCU105 board power-up, the onboard programmable clock sources generate their factory
default frequencies until the system controller has booted and checked the onboard
EEPROM to determine if a frequency value has previously been saved for either onboard
clock source. Previously saved values are restored to the onboard clock sources, which then
output these frequencies until they are reprogrammed to a different value, or the KCU105
board is turned off.
KCU105 Board User Guide
UG917 (v1.4) September 25, 2015
www.xilinx.com
Appendix C: System Controller
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