Datasheet

W5500 Datasheet Version1.0.9 53 / 66
Socket n RX Buffer Block can be accessible with the 16bits Offset Address ranged from
0x0000 to 0xFFFF regardless of the configured size. (Refer to Sn_RX_RD & Sn_RX_WR).
Value (dec)
0
1
2
4
8
16
Buffer size
0KB
1KB
2KB
4KB
8KB
16KB
Ex) Socket 0 RX Buffer Size = 8KB
0x001E
0x08
Sn_TXBUF_SIZE (Socket n TX Buffer Size Register) [R/W] [0x001F] [0x02]
Sn_TXBUF_SIZE configures the TX buffer block size of Socket n. Socket n TX
Buffer Block size can be configured with 1,2,4,8, and 16 Kbytes. If a different size
is configured, the data can’t be normally transmitted to a peer.
Although Socket n TX Buffer Block size is initially configured to 2Kbytes, user can
be re-configure its size using Sn_TXBUF_SIZE. The total sum of Sn_TXBUF_SIZE
cannot be exceed 16Kbytes. When exceeded, the data transmission error is
occurred.
When all Sn_TXBUF_SIZE have been configured, Socket n TX Buffer is allocated
with the configured size in 16KB TX Memory and is assigned sequentially from
Socket 0 to Socket 7.
Socket n TX Buffer Block can be accessible with 16bits Offset Address ranged
from 0x0000 to 0xFFFF regardless of the configured size. (Refer to Sn_TX_WR &
Sn_TX_RD).
Value (dec)
0
1
2
4
8
16
Buffer size
0KB
1KB
2KB
4KB
8KB
16KB
Ex) Socket 0 TX Buffer Size = 4KB
0x001F
0x04
Sn_TX_FSR (Socket n TX Free Size Register) [R] [0x0020-0x0021] [0x0800]
Sn_TX_FSR indicates the free size of Socket n TX Buffer Block. It is initialized to the
configured size by Sn_TXBUF_SIZE. Data bigger than Sn_TX_FSR should not be saved
in the Socket n TX Buffer because the bigger data overwrites the previous saved data
not yet sent. Therefore, check before saving the data to the Socket n TX Buffer, and
if data is equal or smaller than its checked size, transmit the data with