
Functional Overview
170
December 2003 Revised March 2005
SPRS231D
The USB host controller (HC) is a three-port controller that communicates with USB devices at low-speed
(1.5M bit-per-second maximum) and full-speed (12M bit-per-second maximum) data rates. It is compatible
with the Universal Serial Bus Specification Revision 2.0 and the OpenHCI Open Host Controller Interface
Specification for USB, Release 1.0a, which is available on the Internet, and is hereafter called the OHCI
Specification for USB. It is assumed that users of the OMAP5912 USB host controller are already familiar with
the USB Specification and OHCI Specification for USB.
The OMAP5912 OTG controller can use one of the USB host controller ports as part of a USB OTG-capable
connection. When used for an OTG connection, the host controller port acts as the upstream device when
OMAP5912 controls the OTG link, and the USB function controller acts as the downstream device when
OMAP5912 acts as an OTG downstream device.
The USB host controller implements the register set and makes use of the memory data structures defined
in the OHCI Specification for USB. These registers and data structures are the mechanism by which a USB
host controller driver software package can control the USB host controller. The OHCI Specification for USB
also defines how the USB host controller implementation must interact with those registers and data structures
in system memory. The OMAP5912 MPU accesses these registers via the MPU public peripheral bus.
NOTE:
USB 2.0 hi-speed is not supported.
3.6.2 Camera Interface
The camera interface is an 8-bit external port that can be used to accept data from an external camera sensor.
The interface handles multiple image formats synchronized on vertical and horizontal synchronization signals.
Data transfer to the camera interface can be done synchronously or asynchronously.
The camera interface module converts the 8-bit data transfers into 32-bit words and utilizes a 128-word buffer
to facilitate efficient data transfer to memory. Data can be transferred from the camera interface buffer to
internal memory by the system DMA controller or directly by the MPU.
This interface is accessible through the OCP-T1 or OCP-T2 port.
3.6.3 MICROWIRE Serial Interface
The MICROWIRE interface is a serial synchronous interface that can drive up to four serial external
components. This interface is compatible with the MICROWIRE standard and is seen as the master.
MICROWIRE is typically used to transmit control and status information to external peripheral devices or to
transmit data to or from small nonvolatile memories such as serial EEPROMs or serial flash devices.
3.6.4 Real-Time Clock (RTC)
The RTC peripheral provides an embedded real-time clock module that can be directly accessible from the
MPU. The RTC peripheral is powered independently of the OMAP5912 MPU core power.
The RTC module has the following features:
Time information (seconds/minutes/hours) directly in BCD code
Calendar information (day/month/year/day of the week) directly in BCD code up to year 2099
Interrupts generation, periodically (1s/1m/1h/1d period) or at a precise time of the day (alarm function)
30-s time correction
Oscillator frequency calibration