SH7263 Datasheet, PDF (1370/1862 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 25 USB 2.0 Host/Function Module (USB)
(a) FIFO Port Selection
Table 25.20 shows the pipes that can be selected with the various FIFO ports. The pipe to be
accessed is selected using the CURPIPE bit in C/DnFIFOSEL. After the pipe has been selected,
FRDY = 1 should be confirmed before accessing the FIFO port.
Also, the bus width to be accessed should be selected using the MBW bit. The buffer memory
access direction conforms to the DIR bit in PIPEnCFG. The ISEL bit determines this only for the
DCP.
Table 25.20 FIFO Port Access Categorized by Pipe
Pipe
DCP
PIPE1 to PIPE7
Access Method
CPU access
CPU access
DMA access
Port that can be Used
CFIFO port register
CFIFO port register
D0FIFO/D1FIFO port register
D0FIFO/D1FIFO port register
(b) REW Bit
It is possible to temporarily stop access to the pipe currently being accessed, access a different
pipe, and then continue processing using the current pipe once again. The REW bit in
C/DnFIFOSEL is used for this.
If a pipe is selected when the REW bit is set to 1 and at the same time the CURPIPE bit in
C/DnFIFOSEL is set, the pointer used for reading from and writing to the buffer memory is reset,
and reading or writing can be carried out from the first byte. Also, if a pipe is selected with 0 set
for the REW bit, data can be read and written in continuation of the previous selection, without the
pointer used for reading from and writing to the buffer memory being reset.
To access the FIFO port, FRDY = 1 must be confirmed after selecting a pipe.
(c) Reading the Buffer Memory on the SIE (CFIFO Port Reading Direction)
Even in the FRDY = 0 state, when data cannot be read from the buffer memory, confirming the
SBUSY bit in CFIFOSIE and setting 1 for the TGL bit makes it possible for this module to read
and access data on the SIE side. PID = NAK should be set and SBUSY = 0 confirmed, and then
TGL = 1 written. This module is then able to read data from CFIFO. This function can be used
only in the buffer memory reading direction. Also, the BRDY interrupt is generated by operation
of the TGL bit.
Rev. 2.00 Mar. 14, 2008 Page 1336 of 1824
REJ09B0290-0200