SH7670 Datasheet, PDF (813/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 17 USB 2.0 Host/Function Module (USB)
(1) Pipe control register switching procedures
The following bits in the pipe control registers can be modified only when USB communication is
disabled (PID = NAK):
Registers that Should Not be Set in the USB Communication Enabled (PID = BUF) State
• Bits in DCPCFG and DCPMAXP
• The SQCLR and SQSET bits in DCPCTR
• Bits in PIPECFG, PIPEBUF, PIPEMAXP and PIPEPERI
• The ATREPM, ACLRM, SQCLR and SQSET bits in PIPExCTR
• Bits in PIPExTRE and PIPExTRN
In order to modify the above bits from the USB communication enabled (PID = BUF) state, follow
the procedure shown below:
1. Generate a bit modification request with the pipe control register.
2. Modify the PID corresponding to the pipe to NAK.
3. Wait until the corresponding CSSTS bit is cleared to 0 (only when the host controller function
has been selected).
4. Wait until the corresponding PBUSY bit is cleared to 0.
5. Modify the bits in the pipe control register.
The following bits in the pipe control registers can be modified only when the pertinent
information has not been set by the CURPIPE bits in CFIFOSEL, D0FIFOSEL and D1FIFOSEL.
Registers that Should Not be Set When CURPIPE in FIFO-PORT is set.
• Bits in DCPCFG and DCPMAXP
• Bits in PIPECFG, PIPEBUF, PIPEMAXP and PIPEPERI
In order to modify pipe information, the CURPIPE bits should be set to the pipes other than the
pipe to be modified. For the DCP, the buffer should be cleared using BCLR after the pipe
information is modified.
Rev. 1.00 Nov. 14, 2007 Page 787 of 1262
REJ09B0437-0100