1.2 Usb Device/Host Selection; Usb Device/Host Function Selection Procedure; Usb Port State Change Detection Status; Usb Port State Change Detection Status Usage Examples - Epson S2R72V18 Technical Manual

1. Functions

1.2 USB Device/Host Selection

Either USB device or host functions can be selected when using USB Port 0. For USB Port 1, only USB
host function can be selected.
Selecting the USB device function (Device mode) enables shared register and device register bits and
functions.
Selecting the USB host function (Host mode) enables shared register and host register bits and functions.
1.2.1

USB Device/Host Function Selection Procedure

Clearing the HostDeviceSel(0).HOSTxDEVICE bit for USB Port 0 enables the device function, and
setting this bit enables the host function. It's possible to switch between Host and Device modes when
the Port 0 power management state is SLEEP. Table 1-1 shows the USB device/host selection settings.
Item
USB device/host
selection
1.2.2

USB Port State Change Detection Status

This LSI includes a function for detecting USB port states.
This function can be used in both SLEEP and ACTIVE states (refer to "1.5 Power Management
Functions").
1.2.2.1

USB Port State Change Detection Status Usage Examples

The examples given here use device port or host port change status.
1.2.2.1.1

Device Port Change Status

This status indicates that a change in the VBUS_0 terminal state for USB Port 0 in Device mode.
Table 1-2 lists registers for device port change status.
Item
VBUS terminal change
status
VBUS terminal change
status enable
VBUS terminal state
2
Table 1-1 USB Device/Host function selection settings
Register/bit
HostDeviceSel(0).HOSTxDEVICE
Table 1-2 Device port change status registers
Register/bit
USB_DeviceIntStat(0).VBUS_Changed
USB_DeviceIntEnb(0).EnVBUS_Changed
D_USB_Status(0).VBUS
Selects USB Device or Host mode. Allows use of
registers and functions corresponding to the
mode selected.
1: Host mode
0: Device mode
Indicates a change in the device port
VBUS_0 terminal state.
Permits/prevents assertion of the
MainIntStat.USB_DeviceIntStat bit by
USB_DeviceIntStat.VBUS_Changed.
Indicates the device port VBUS_0 terminal
state.
EPSON
S2R72V18 Technical Manual (Rev.1.00)
Description
Description