W5100S datasheet(60/110 Pages) WIZNET

60 / 110 page

60 / 110

W5100S Datasheet Version1.2.5

When Write Offset Address calculated, it is cautious to over the boundary Address (n=0,1,2 :

gSn_TX_BASE ∼ gSn+1_TX_BASE, n=3 : gS3_TX_BASE ∼ 0xC000) of SOCKET n TX Buffer Block.

If there is no response from Peer against of transmitted Data Packet within the Retransmission

Time, Sn_IR [TIMEOUT] is set to ‘1’.

{

/* calculate SOCKETn TX Buffer Size & Offset Address */

gSn_TX_MAX = Sn_TXBUF_SIZE * 1024;

get_offset = Sn_TX_WR & gSn_TX_MASK;

/* check the max size of DATA(send_size) & Free Size of SOCKETn TX

Buffer(Sn_TX_FSR)*/

if( send_size >gSn_TX_MAX ) send_size = gSn_TX_MAX;

while(send <= Sn_TX_FSR); // Wait until SOCKET n TX Buffer is free */

/* If you don’t want to wait TX Buffer Free

send_size = Sn_TX_FSR; // write Data as size of Free Buffer

/* calculate Write Offset Address */

get_start_address = gSn_TX_BASE + get_offset;

/* if overflow the upper boundary of SOCKET n TX Buffer */

If( (get_offset + send_size) > gSn_TX_MAX )

{

/* copy upper size bytes of source_address to get_start_address

- source_address is the start address of user data */

upper_size = gSn_TX_MAX – get_offset;

memcpy(source_address, get_start_address, upper_size);

/* copy the Remained Size Bytes of source_address to gSn_TX_BASE */

source_address += upper_size;

remained_size = send_size – upper_size;

memcpy(source_address, gSn_TX_BASE, remained_size);

}

else

{

/* copy send_size bytes of source_address to get_start_address

- source_address is the start address of user data */

W5100S Datasheet(PDF) 60 Page - WIZnet Co., Ltd