EVB-B1+ WIZnet, EVB-B1+ Datasheet - Page 78

• Manufacturer Part Number: EVB-B1+
• Description: Development Boards & Kits - ARM W3150A+EVAL BOARD BASED ON AVR
• Manufacturer: WIZnet

Specifications of EVB-B1+

• Rohs: yes
• Product: Evaluation Boards
• Interface Type: RS-232, SPI
• Operating Supply Voltage: 3.3 V, 5 V
• Data Bus Width: 8 bit
• Dimensions: 50 mm x 40 mm
• Processor Series: ATmega128

to document ‘RFC1541’ for detailed explanation for each field of DHCP message Format. op Field of the first
byte decided Request/Reply, and fields after ciaddr is used to deliver network information, and options field
of 312 byte is used to transmit message type or the information such as Client Identifier.
DHCP Message of <Fig 3.26> is managed by RIP_MSG Data Type defined in <Table 3-33>. Refer to
“inet/dhcp.h”
To take a brief look at the Option Field of DHCP Message, Option Field has the format of <Fig 3.27>, it
contains Magic Cookie Field, a Lease Identification Cookie with the size of 4 Byte and Code Set ranged from
typedef struct _RIP_MSG
{
}RIP_MSG;
u_char op;
u_char htype;
u_char hlen;
u_char hops;
u_long xid;
u_int
u_int
u_char ciaddr[4];
u_char yiaddr[4];
u_char siaddr[4];
u_char giaddr[4];
u_char chaddr[16];
u_char sname[64];
u_char file[128];
u_char OPT[312];
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secs;
flags;
<Table 3-32: DHCP Message Data Type>
<Fig 3.26: DHCP Message Format>
// DHCP_BOOTREQEUST or DHCP_BOOTREPLY
// DHCP_HTYPE10MB
// DHCP_HLENETHERNET
// DHCP_HOPS
// DHCP_XID
// DHCP_SECS
// DHCP_FLAGSBROADCAST
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