Espressif ESP32-S2 Programming Manual page 1243

Chapter 2. API Reference
If set, the unity framework will print the backtrace information before jumping back to the test menu.
The jumping is usually occurs in assert functions such as TEST_ASSERT, TEST_FAIL etc.
Default value:
• No (disabled)
USB-OTG Contains:
• CONFIG_USB_HOST_HW_BUFFER_BIAS
• CONFIG_USB_HOST_CONTROL_TRANSFER_MAX_SIZE
CONFIG_USB_HOST_CONTROL_TRANSFER_MAX_SIZE
Largest size (in bytes) of transfers to/from default endpoints
Found in: Component config
Each USB device attached is allocated a dedicated buffer for its OUT/IN transfers to/from the device's
control endpoint. The maximum size of that buffer is determined by this option. The limited size of the
transfer buffer have the following implications: - The maximum length of control transfers is limited -
Device's with configuration descriptors larger than this limit cannot be supported
Default value:
• 256
CONFIG_USB_HOST_HW_BUFFER_BIAS
Hardware FIFO size biasing
Found in: Component config
The underlying hardware has size adjustable FIFOs to cache USB packets on reception (IN) or for
transmission (OUT). The size of these FIFOs will affect the largest MPS (maximum packet size) and
the maximum number of packets that can be cached at any one time. The hardware contains the fol-
lowing FIFOS: RX (for all IN packets), Non-periodic TX (for Bulk and Control OUT packets), and
Periodic TX (for Interrupt and Isochronous OUT packets). This configuration option allows biasing the
FIFO sizes towards a particular use case, which may be necessary for devices that have endpoints with
large MPS. The MPS limits for each biasing are listed below:
Balanced: - IN (all transfer types), 408 bytes - OUT non-periodic (Bulk/Control), 192 bytes (i.e., 3 x
64 byte packets) - OUT periodic (Interrupt/Isochronous), 192 bytes
Bias IN: - IN (all transfer types), 600 bytes - OUT non-periodic (Bulk/Control), 64 bytes (i.e., 1 x 64
byte packets) - OUT periodic (Interrupt/Isochronous), 128 bytes
Bias Periodic OUT: - IN (all transfer types), 128 bytes - OUT non-periodic (Bulk/Control), 64 bytes
(i.e., 1 x 64 byte packets) - OUT periodic (Interrupt/Isochronous), 600 bytes
Available options:
• Balanced (USB_HOST_HW_BUFFER_BIAS_BALANCED)
• Bias IN (USB_HOST_HW_BUFFER_BIAS_IN)
• Periodic OUT (USB_HOST_HW_BUFFER_BIAS_PERIODIC_OUT)
Virtual file system Contains:
• CONFIG_VFS_SUPPORT_IO
CONFIG_VFS_SUPPORT_IO
Espressif Systems
> USB-OTG
> USB-OTG
1232
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