R8A66597FP Datasheet, PDF (88/185 Pages) Renesas Technology Corp – ASSP (USB2.0 2 Port Host/1 Port Peripheral Controller)

R8A66597FP/DFP/BG
2.16.6 Pipe disabled at the end of transfer bit (SHTNAK)
This bit is valid when Pipe1 to Pipe5 are selected and is receiving. When the software has set "1" to this bit for the
receiving pipe, when the transfer end is determined for the selected pipe, the controller modifies the PID bit of the
selected pipe to "NAK". The controller determines transfer end when either one of the following conditions are fulfilled:
(1) When a short packet data (including a zero-length packet) is received normally.
(2) When a transaction counter is used and a packet of transaction counter portion is received normally.
This bit can be modified when "CSSTS=0" and "PID=NAK".
To modify this bit after changing the PID bit of the corresponding pipe from "BUF" to "NAK", check that "CSSTS=0"
and "PBUSY=0", and modify the bit. However, when the controller has modified the PID bit to "NAK", it is not
necessary to check the PBUSY bit.
Write "0" to this bit for the transmission direction pipe".
2.16.7 Transfer direction bit (DIR)
When the software has written "0" to this bit and the controller has set the selected pipe to receive and "1" is written to
this bit, the controller uses the selected pipe in transmission.
This bit can be modified when "CSSTS=0", "PID=NAK", and when the pipe in the CURPIPE bit is not written. Execute
USB communication using the selected pipe, use the software to continuously write "ACLRM=1" and "ACLRM=0",
clear the FIFO buffer assigned to the selected pipe, and then modify this bit in addition to the status of the above three
registers.
To modify this bit after changing the PID bit of the corresponding pipe from "BUF" to "NAK", check that "CSSTS=0"
and "PBUSY=0", and modify the bit. However, when the controller has modified the PID bit to "NAK", it is not
necessary to check the PBUSY bit.
2.16.8 Endpoint number bit (EPNUM)
In this bit, use the software to write the endpoint number related to the selected pipe. However, writing "0000" indicates
that the pipe is not being used.
This bit can be modified when "CSSTS=0", "PID=NAK", and when the in the CURPIPE bit is not written.
To modify this bit after changing the PID bit of the corresponding pipe from "BUF" to "NAK", check that "CSSTS=0"
and "PBUSY=0", and modify the bit. However, when the controller has modified the PID bit to "NAK", it is not
necessary to check the PBUSY bit.
Set the combination of the DIR bit and EPNUM bit so that they are not duplicated with the other pipe settings
("EPNUM=000" (selected pipe not used) settings can be duplicated).
Rev1.01 Oct 17, 2008 page 88 of 183