SH7670 Datasheet, PDF (834/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 17 USB 2.0 Host/Function Module (USB)
17.4.6 Bulk Transfers (PIPE1 to PIPE5)
The buffer memory specifications for bulk transfers (single/double buffer setting, or
continuous/non-continuous transfer mode setting) can be selected. The maximum size that can be
set for the buffer memory is 2 kbytes. The buffer memory state is controlled by this module, with
a response sent automatically for a PING packet/NYET handshake.
(1) PING Packet Control when the Host Controller Function is Selected
This module automatically sends a PING packet in the OUT direction.
On receiving an ACK handshake in the initial state in which PING packet sending mode is set,
this module sends an OUT packet as noted below. Reception of an NAK or NYET handshake
returns this module to PING packet sending mode. This control also applies to the control
transfers in the data stage and status stage.
1. Sets OUT data sending mode.
2. Sends a PING packet.
3. Receives an ACK handshake.
4. Sends an OUT data packet.
5. Receives an ACK handshake.
(Repeats steps 4 and 5.)
6. Sends an OUT data packet.
7. Receives an NAK/NYET handshake.
8. Sends a PING packet.
This module is returned to PING packet sending mode by a power-on reset, receiving a
NYET/NAK handshake, setting or clearing the sequence toggle bits (SQSET and SQCLR), and
setting the buffer clear bit (ACLRM) in PIPEnCTR.
Rev. 1.00 Nov. 14, 2007 Page 808 of 1262
REJ09B0437-0100