SH7670 Datasheet, PDF (784/1292 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 Operation
17.4.1 System Control and Oscillation Control
This section describes the register operations that are necessary to the initial settings of this
module, and the registers necessary for power consumption control.
(1) Resets
Table 17.16 lists the types of controller resets. For the initialized states of the registers following
the reset operations, see section 17.3, Register Description.
Table 17.16 Types of Reset
Name
Power-on reset
USB bus reset
Operation
Low level input from the RESETP pin or writing of 1 to the RST bit in USBEXR.
Note: Power-on resets described in this manual include resets using the RST
bit as well as those using the RESETP pin
Automatically detected by this module from the D+ and D− lines when the
function controller function is selected
(2) Controller Function Selection
This module can select the host controller function or function controller function using the
DCFM bit in SYSCFG. Changing the DCFM bit should be done in the initial settings immediately
after a power-on reset or in the D+ pull-up disabled (DPRPU = 0) and D + /D − pull-down
disabled (DRPD = 0) state.
(3) Enabling High-Speed Operation
This module can select a USB communication speed (communication bit rate) using software.
When the host controller function is selected, either of the high-speed operation or full-speed/low-
speed operation can be selected. In order to enable the high-speed operation for this module, the
HSE bit in SYSCFG should be set to 1. If high-speed mode has been enabled, this module
executes the reset handshake protocol, and the USB communication speed is set automatically.
The results of the reset handshake can be confirmed using the RHST bit in DVSTCTR.
If high-speed operation has been disabled, this module operates at full-speed or low-speed. If the
function controller function is also selected, this module operates at full-speed.
Rev. 1.00 Nov. 14, 2007 Page 758 of 1262
REJ09B0437-0100