Artesyn COMX-P4080-2G-ENP2 Installation and Use (August 2014) - Manual (Page 53)

Functional Description
COMX-P4080-2G-ENP2 Installation and Use (6806800P63B) 53
U-boot has the following considerations:
 U-boot should provide commands for setting RTC date/time and getting RTC date/time.
4.18.5 I2C Device Clock Generator
The clock generator ICS9FG104 is located on I2C1, U17 and the device address is 0xDC.
The ICS9FG104 is a Frequency Timing Generator that provides four differential output pairs
that are compliant to the Intel CK410 specification. It also provides support for PCI-Express and
SATA. The part synthesizes several output frequencies from either a 14.31818 MHz crystal or a
25 MHz crystal. The device can also be driven by a reference clock input instead of a crystal. It
provides outputs with cycle-to-cycle jitter of less than 50 ps and output-to output skew of less
than 35 ps. The ICS9FG104 also provides a copy of the reference clock.
Frequency selection can be accomplished via strap pins or SMBus control. By default, strap pins
work.
For COMX-P4080-2G-ENP2, the input clock for ICS9FG104 is 25 MHz and three differential
output pairs are provided. First pair are connected to SerDes Bank 1, second pair are connected
to x2 Aurora Connector, and third pair are connected to COM Express connector.
The forth output pairs are not connected.
When using strap pins to select output frequency, SEL14M_25M# (FS3) is attached to ground
(0) by option resistor. FS2 and FS1 have internal 120K pull down and the option resistors should
not be soldered. FS0 is controlled by GPIO23 and S1.2. When FS0 is 0 (low level), 100MHz clock
output is selected and When FS0 is 1 (high level), 125MHz clock output is selected.
4.18.6 I2C Device USB
I2C device consists of one USB2514 located on I2C2, U25 and the device address is 0x58.
USB2514 is a USB hub controller IC with four downstream ports for embedded USB solutions.
The 4-port hub is fully compliant with the USB 2.0 Specification and will attach to an upstream
port as a Full-Speed Hub or as a Full-/High-Speed Hub, and High Speed (if operating as a High-
Speed Hub) downstream devices on all of the enabled downstream ports.