9.2.6.4 USB Transfer Event Definitions

A transfer is composed of one or several transactions as shown in the table below.

Table 9-2. USB Transfer Events
TransferTransaction
DirectionType
CONTROL (bidirectional)Control Transfer (1)
  • Setup transaction → Data IN transactions → Status OUT transaction
  • Setup transaction → Data OUT transactions → Status IN transaction
  • Setup transaction → Status IN transaction
IN (device toward host)Bulk IN Transfer
  • Data IN transaction → Data IN transaction
Interrupt IN Transfer
  • Data IN transaction → Data IN transaction
Isochronous IN Transfer (2)
  • Data IN transaction → Data IN transaction
OUT (host toward device)Bulk OUT Transfer
  • Data OUT transaction → Data OUT transaction
Interrupt OUT Transfer
  • Data OUT transaction → Data OUT transaction
Isochronous OUT Transfer (2)
  • Data OUT transaction → Data OUT transaction
Note:
  1. Control transfer must use endpoints with one bank and can be aborted using a stall handshake.
  2. Isochronous transfers must use endpoints configured with two or three banks.

An endpoint handles all transactions related to the type of transfer for which it has been configured.

Table 9-3. UDPHS Endpoint Description
Endpoint #MnemonicNb BanksDMAHigh BandwidthMax. Endpoint SizeEndpoint Type
0EPT_01NN64Control
1EPT_12YN1024Ctrl/Bulk/Iso(1)/Interrupt
2EPT_22YN1024Ctrl/Bulk/Iso(1)/Interrupt
3EPT_33YY1024Ctrl/Bulk/Iso(1)/Interrupt
4EPT_43YY1024Ctrl/Bulk/Iso(1)/Interrupt
5EPT_53YY1024Ctrl/Bulk/Iso(1)/Interrupt
6EPT_63YY1024Ctrl/Bulk/Iso(1)/Interrupt
Note:
  1. In Isochronous (Iso) mode, it is preferable that the high bandwidth capability is available.

The size of the internal DPRAM is 16448 bytes, covering the memory need for the endpoints, hence enabling static allocation of the memory for all endpoints.

Suspend and resume are automatically detected by the UDPHS device, which notifies the processor by raising an interrupt.