SH7263 Datasheet, PDF (1374/1862 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 25 USB 2.0 Host/Function Module (USB)
(h) Method of Changing Setting of MBW Bits when Selected CURPIPE Is Set to Buffer
Memory Read Direction
Write to the MBW bits in the FIFO port select registers (CFIFOSEL, D0FIFOSEL, and
D1FIFOSEL) and set the CURPIPE bits simultaneously. When the DCP setting (CURPIPE = 000)
is selected in the CFIFO register, set the CURPIPE bits or ISEL bit and write to the MBW bits
simultaneously.
Follow the procedure below to change the setting of only the MBW bits for the currently selected
pipe. However, once a buffer memory read operation has started, do not change the setting of the
MBW bits until all the data has been read.
It is possible to change the setting of only the MBW bits directly when the selected CURPIPE is
set to the buffer memory write direction. However, once a buffer memory write operation has
started, do not change the bit width from 8 bits to 16 or 32 bits, or from 16 bits to 32 bits.
• When CURPIPE of DFIFO0, DFIFO1, or CFIFO is set to other than DCP (000)
Start
[1]
Set CURPIPE to 000
[2]
Insert wait of at least
120 ns + 5 bus cycles
[1] Set CURPIPE to a setting other than the current setting.
[2] Changing the CURPIPE setting in succession requires
an access cycle of at least 120 ns plus five bus cycles.
[3] Set the MBW bits to the desired value and the CURPIPE
bits to the pipe setting preceding the change in [1].
[3]
Set MBW and CURPIPE
simultaneously
MBW setting change completed
Figure 25.14 Example of Changing the MBW Setting when CURPIPE of DFIFO0, DFIFO1,
or CFIFO Is Set to Other Than DCP (000)
Rev. 2.00 Mar. 14, 2008 Page 1340 of 1824
REJ09B0290-0200