Data Gen

Based on the requests from the Data Store module, the Data Gen module generates Ethernet packets with the appropriate control and status data to be transmitted to IAP Target.

The Ethernet packet consists of the following fields:
The Data Gen module uses this custom packet structure and fields while generating control and data Ethernet packets in this demo design. The Control Ethernet packet of length 92 bytes carries the necessary information to IAP Target for the following activities.

The data packet of length 1052 bytes carries the SPI image to the target, which is stored in the External SPI Flash of IAP Target. Control packet is also used to send image authentication and program requests. For any given data transfer, a total of 2 KB data (2 data packets) are transmitted every time.

The following table lists the byte format of a control and data packet.

Table 1. Ethernet Packet Structure (Control and Data)
Byte Number Size Field Value
1-8 8 bytes

Destination Address

Source Address



9-16 8 bytes Source Address 32'hD5576610
Ethernet Type 16’h0700

16’h0004 – Control

16’h0005 – Payload

16’h0007 – IAP Authenticate

16’h0008 – IAP Program

16’h0009 – Send version Number

16’h000A – Clear all interrupts

16-23 8 bytes Zero’s 32’h00000000
Length 0x0040 – 64 bytes
0x0400 – 1024 bytes
Offset 16’h0000
24-87 36 bytes Payload (Control Information)

64’h0000000000000000 – For Control Info packet

{Burst size, Last burst info} – For Authenticate, Program packets

Data Packet
24-1047 1024 bytes Payload (IAP Data) 1024 Bytes of IAP Data
Last 4 4 bytes FCS Core10GMAC computes the FCS and appends to the Frame before transmitting out.