Code template for the COM-1800 platform
We recommend this code as a starting point to any new project.
It includes the drivers for GbE LAN MAC, 2 TCP servers, DDR3 SODIMM and AD5621 serial DAC


GbE LAN:
The COM-5401 Ethernet MAC is included as a .ngc file with the following fixed
configuration:
	MII_SEL => '0',   	   -- select which MII interface: 0 = RGMII, 1 = GMII/MII
	PHY_ADDR => "00111",   -- PHY_AD0/1 pulled-up, PHY_AD2 pulled-up in .xdc file.
	CLK_FREQUENCY => 125,
	PLATFORM => 7,	       -- 7 series Xilinx FPGA
	TARGET_PHY => 3,       -- target PHY: KSZ9031
	NO_1000 => '0',	-- advertize full 10/100/1000 Mbps
	INTERNAL_PHY_TX_CLKS_DELAYS => '0',
	INTERNAL_PHY_RX_CLKS_DELAYS => '0',
	SIMULATION => '0'
Firmware revision: com-5401_012d

TCP servers:
The COM-5402 IP stack is included as .ngc file with the following fixed configuration:
		NUDPTX => 1,
		NUDPRX => 1,
		NTCPSTREAMS => 2,  
		IGMP_EN => '1',	-- enable multicast UDP
		CLK_FREQUENCY => 125,	-- CLK_P 125 MHz, as time reference
		TX_IDLE_TIMEOUT => 50,	-- 50*4us = 200us 
		TCP_KEEPALIVE_PERIOD => 60,
		SIMULATION => '0'
Firmware revision: com-5402 TCP server 007s


two TCP servers are implemented. One (at port 1028) reserved for monitoring and control
to communicate with the ComBlock Control Center or the API. The other (at port 1024) for
the user's application.

Two reference clocks are possible:
a 19.2 MHz TCXO or a 10 MHz external frequency reference through the J6 coaxial connector.
The clock is selected through control register CREG0 bit 0

AD5621 serial DAC driver:
12-bit serial DAC