Overview
13-2
13.1 Overview
The USB function module supports the implementation of a full-speed device
fully compliant with the USB 1.1 standard. It provides an interface between the
MPU core (TI925T) and the USB wire, and it handles USB transactions with
minimal TI925T intervention.
The module supports one control endpoint (EP0) (IN and OUT), up to 15 IN
endpoints, and up to 15 OUT endpoints. The exact endpoint configuration is
software programmable. For each endpoint, the specific parameters of a con-
figuration are the size in bytes, the direction (IN, OUT), the type (bulk/interrupt
or isochronous), and the associated number.
The module also supports three DMA channels for IN endpoints and three
DMA channels for OUT endpoints for either bulk/interrupt or isochronous
transactions.
This chapter uses terminology defined in USB1.1 Standard. Reader familiarity
with this Standard is assumed. All references to local host (LH) in this chapter
refer to the MPU processor.
Figure 13–1 shows the OMAP5910 device with the USB function module high-
lighted. Figure 13–2 shows the connection of the USB function module within
the OMAP5910 in more detail.
13.1.1 OMAP5910 Inputs/Outputs
Several configurations are possible for the USB function:
-
USB function usable with internal transceiver (default configuration)
-
USB function usable with external transceivers
-
USB function not usable
See the details of these configurations in the section 7.14, USB Host
Controller Overview.
13.1.2 USB Function Interrupts
The USB function generates three interrupts:
1) General USB interrupt (including endpoint 0, DMA, and device states
interrupts), IRQ_GENI_ON: Connected to the MPU level 2 interrupt
handler, line 20 (level-sensitive)
2) Non-ISO endpoint-specific Interrupt, IRQ_NON_ISO_ON: Connected to
the MPU level 2 interrupt handler, line 30 (level-sensitive)
3) Start of frame (SOF) interrupt for ISO transactions, IRQ_ISO_ON:
Connected to the MPU level 2 interrupt handler, line 29 (level-sensitive)