Datasheet

Figure 3. Buffer descriptor table
Software should manage buffers for USBFS by updating the BDT when needed. This allows USBFS to manage data transmission
and reception, while the microprocessor performs communication overhead processing and other function-dependent
applications.
4.2 Endpoint Buffer
The buffer of the control endpoint is not fixed. When receiving the Setup data, the EP0 buffer is
s_UsbDeviceKhciState.setupPacketBuffer[8*2]; When processing the IN transaction, the EP0 buffer is generally an array of
descriptors: g_UsbDeviceDescriptor[], g_UsbDeviceConfigurationDescriptor[], etc. The buffer configuration of non-control
endpoint is shown in Table 6.
Table 6. EP buffer configuration
VCOM number Endpoint direction EP Buffer
VCOM1 1 OUT s_currRecvBuf[0][64]
VCOM1 1 IN s_currSendBuf[0][64]
VCOM2 2 OUT s_currRecvBuf[1][64]
VCOM2 2 IN s_currSendBuf[1][64]
VCOM3 3 OUT s_currRecvBuf[2][64]
Table continues on the next page...
NXP Semiconductors
Endpoint Buffer Configuration
USB to Multi VCOM on K32L2 Series MCU, Rev. 0, November 2019
Application Note 6 / 25