Espressif ESP32-S2 User Manual

Chapter 2. API Reference
CONFIG_LWIP_L2_TO_L3_COPY
Enable copy between Layer2 and Layer3 packets
Found in: Component config > LWIP
If this feature is enabled, all traffic from layer2(WIFI Driver) will be copied to a new buffer before send-
ing it to layer3(LWIP stack), freeing the layer2 buffer. Please be notified that the total layer2 receiving
buffer is fixed and ESP32 currently supports 25 layer2 receiving buffer, when layer2 buffer runs out of
memory, then the incoming packets will be dropped in hardware. The layer3 buffer is allocated from
the heap, so the total layer3 receiving buffer depends on the available heap size, when heap runs out of
memory, no copy will be sent to layer3 and packet will be dropped in layer2. Please make sure you fully
understand the impact of this feature before enabling it.
Default value:
• No (disabled)
CONFIG_LWIP_IRAM_OPTIMIZATION
Enable LWIP IRAM optimization
Found in: Component config > LWIP
If this feature is enabled, some functions relating to RX/TX in LWIP will be put into IRAM, it can
improve UDP/TCP throughput by >10% for single core mode, it doesn’t help too much for dual core
mode. On the other hand, it needs about 10KB IRAM for these optimizations.
If this feature is disabled, all lwip functions will be put into FLASH.
Default value:
• No (disabled)
CONFIG_LWIP_TIMERS_ONDEMAND
Enable LWIP Timers on demand
Found in: Component config > LWIP
If this feature is enabled, IGMP and MLD6 timers will be activated only when joining groups or receiving
QUERY packets.
This feature will reduce the power consumption for applications which do not use IGMP and MLD6.
Default value:
• Yes (enabled)
CONFIG_LWIP_MAX_SOCKETS
Max number of open sockets
Found in: Component config > LWIP
Sockets take up a certain amount of memory, and allowing fewer sockets to be open at the same time
conserves memory. Specify the maximum amount of sockets here. The valid value is from 1 to 16.
Range:
• from 1 to 16
Default value:
• 10
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Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English