Instruction manual

Renesas USB MCU and USB ASSP USB Basic Host and Peripheral firmware
R01AN0512EJ0210 Rev.2.10 Page 153 of 157
Apr 1, 2013
11.1.3 Notes on Data Reception
When the received data exceeds the buffer size, data is read from the FIFO buffer up to the buffer size and transfer ends.
In Host mode, when the pipe information table is updated in the HCD API function, the following settings are
implemented.
Please carry out the following setup to a pipe information table at the time of Peripheral operation.
• Enable the SHTNAK function for the data receive pipe.
• The data receive pipe processes requests with the BFRE function enabled. (When the Ep table is set to
USB_D0DMA = DTC transfer, the pipe configuration is set to BFRE ON.)
• Use the transaction counter for the data receive pipe.
The area of integral multiples of the max packet size is necessary for the buffer where the received data is stored. When
the max packet size is 64 bytes, the necessary size of buffer example is shown to the receive data size below.
Table 11-4 Buffer size example (max packet size is 64bytes)
Receive data size Buffer size [bytes]
64 bytes or less 64 (max packet size)
65 bytes or more and 128 bytes or less 128 (max packet size times two)
… …
449 bytes or more and 512 bytes or less 512 (max packet size times eight)
… …
[Note]
When EXDMA is used, RX MCU internal RAM can not be used. EXDMA can use the external bus only.