PGP Ethernet Version1

Support "point-to-point" and "network" mode
- "point-to-point" by default (better logic optimization)
Layer 2 Ethernet framing
- Wrapper on the Ethernet MAC
- Targeting 100G Hard IP MAC
  - 512-bit AXI Stream interface
Chuck up the stream to MAX_SIZE=1024B (default)
- 92.1% efficient = 1024B/(1024B + 4B FCS + 12B intergap + 8B preamble + 64B PGP Ethernet Header)
- 95.9% efficient = 2048B/(2048B + 4B FCS + 12B intergap + 8B preamble + 64B PGP Ethernet Header)
- 97.9% efficient = 4096B/(4096B + 4B FCS + 12B intergap + 8B preamble + 64B PGP Ethernet Header)
- 98.9% efficient = 8196B/(8196B + 4B FCS + 12B intergap + 8B preamble + 64B PGP Ethernet Header)
- Smaller MAX_SIZE lower the latency for publishing the virtual channel "pause" status to the remote side
Use the MAC's FCS for error checking
In network mode, using the global ETH pause (IEEE 802.3x) to flow control between the ETH ports on the network
- Not using Priority Flow Control (IEEE 802.1Qbb)
Virtual channel flow control done at the L2 layer

Word#	Word's BYTE	Name	Description	Note
0	[5:0]	DestMac	Destination MAC	Network mode only
0	[11:6]	SrcMac	Source MAC	Network mode only
0	[15:12]	EtherType	TBD Value	Network mode only
0	16	Version	0x1	Hard coded
0	17	TID	Transaction ID	Increments once per packet Used for out-of-order frame reorganizing in network mode
0	[19:18]	Pause	Virtual Channel Pause	1 bit per Virtual Channel
0	20	VC	Virtual Channel Index	BIT[3:0]: Virtual Channel Index BIT[7:4]: Reserved
0	21	tUserFirst	first 8-bits of tUser
0	22	tUserLast	last 8-bits of tUser
0	[31:23]	Reserved	Reserved	Zeros
0	[47:32]	OpCodeData	128-bit OP-code Data	Supports 64-bit timestamp + more information
0	[63:48]	UserData	128-bit User Data	Sampled every packet sent
1	[63:0]	Payload	User Payload Data
...	...	...	...
(MAX_SIZE/64)	[63:0]	Payload	User Payload Data

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