SH7203 Datasheet, PDF (1237/1686 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 23 USB 2.0 Host/Function Module (USB)
Also, this module automatically judges the direction bit (bit 8 of the bmRequestType) and the
request data length (wLength) of the USB request that was received, and then distinguishes
between control read transfers, control write transfers, and no-data control transfers, and controls
the stage transition. For a wrong sequence, the sequence error of the control transfer stage
transition interrupt is generated, and the software is notified. For information on the stage control
of this module, see figure 23.7.
(b) Data Stage
Data transfers corresponding to USB requests that have been received should be done using the
DCP. Before accessing the DCP buffer memory, the access direction should be specified using the
ISEL bit in CFIFOSEL.
If the data being transferred is larger than the size of the DCP buffer memory, the data transfer
should be carried out using the BRDY interrupt for control write transfers and the BEMP interrupt
for control read transfers.
With control write transfers during high-speed operation, the NYET handshake response is carried
out based on the state of the buffer memory. For information on the NYET handshake, see section
23.4.6 (2), NYET Handshake Control when the Function Controller Function is Selected.
(c) Status Stage
Control transfers are terminated by setting the CCPL bit to 1 with the PID bit in DCPCTR set to
PID = BUF.
After the above settings have been entered, this module automatically executes the status stage in
accordance with the data transfer direction determined at the setup stage. The specific procedure is
as follows.
1. For control read transfers:
The zero-length packet is received from the USB host, and this module sends an ACK
response.
2. For control write transfers and no-data control transfers:
This module sends a zero-length packet and receives an ACK response from the USB host.
Rev. 2.00 Apr. 16, 2008 Page 1207 of 1652
REJ09B0313-0200