USB Host Controller
1534
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Universal Serial Bus (USB)
29.2.2 USB Host Controller Differences From OHCI Specification for USB
The USB host controller implementation does not implement every aspect of the functionality defined in
the
OHCI Specification for USB
. The differences focus on the OHCI ownership change interrupt. Other
restrictions are imposed by the effects of the device pin multiplexing options.
29.2.2.1 Top-Level Pin Multiplexing and OHCI Registers
The RM4x microcontroller supports two USB Host ports and one USB Device port. The USB device port
interface signals are multiplexed with the second USB Host port interface signals. All USB interface
signals are also multiplexed with other functions on the RM4x microcontrollers. The configuration of these
multiplexors is done by configuring the I/O Multiplexing Module control registers. Refer to the
I/O
Multiplexing and Control Module (IOMM)
chapter for more information on the sequence for configuring
these control registers.
The OHCI RHDESCRIPTORA register always reports two available USB host ports, regardless of the top-
level pin multiplexing settings.
Table 29-1. USB Host / Device Interface Signal Multiplexing and Control
USB Host / Device Interface Signal Name
Control for Selecting
USB Host Signal
Control for Selecting
USB Device Signal
USB1.OVERCURRENT
PINMMR14 [7:0] = 08h
-
USB1.RCV
PINMMR13 [31:24] = 08h
-
USB1.VM
PINMMR12 [31:24] = 08h
-
USB1.VP
PINMMR12 [23:16] = 08h
-
USB1.PORTPOWER
PINMMR21 [15:8] = 02h
-
USB1.SPEED
PINMMR19 [15:8] = 04h
-
USB1.SUSPEND
PINMMR20 [23:16] = 08h
-
USB1.TXDAT
PINMMR18 [31:24] = 02h
-
USB1.TXEN
PINMMR17 [7:0] = 04h
-
USB1.TXSE0
PINMMR18 [15:8] = 02h
-
USB2.OVERCURRENT / USB_FUNC.VBUSI
PINMMR1 [15:8] = 08h
PINMMR1 [15:8] = 10h
USB2.RCV / USB_FUNC.RXDI
PINMMR0 [7:0] = 02h
PINMMR0 [7:0] = 04h
USB2.VM / USB_FUNC.RXDMI
PINMMR1 [7:0] = 02h
PINMMR1 [7:0] = 04h
USB2.VP / USB_FUNC.RXDPI
PINMMR0 [15:8] = 02h
PINMMR0 [15:8] = 04h
USB2.PORTPOWER / USB_FUNC.GZO
PINMMR6 [7:0] = 02h
PINMMR6 [7:0] = 04h
USB2.SPEED / USB_FUNC.PUENON
PINMMR4 [31:24] = 04h
PINMMR4 [31:24] = 08h
USB2.SUSPEND / USB_FUNC.SUSPENDO
PINMMR6 [23:16] = 04h
PINMMR6 [23:16] = 08h
USB2.TXDAT / USB_FUNC.TXDO
PINMMR2 [7:0] = 02h
PINMMR2 [7:0] = 04h
USB2.TXEN / USB_FUNC.PUENO
PINMMR4 [23:16] = 04h
PINMMR4 [23:16] = 08h
USB2.TXSE0 / USB_FUNC.SE0O
PINMMR3 [15:8] = 02h
PINMMR3 [15:8] = 04h
29.2.2.2 No Ownership Change Interrupt
The USB host controller does not implement the OHCI ownership change interrupt.