The ISP1161A1 is a single-chip Universal Serial Bus (USB) host controller and peripheral controller. The host controller portion of the ISP1161A1 complies with Universal Serial Bus Specification Rev. 2.0, supporting data transfer at full-speed (12 Mbit/s) and low-speed (1.5 Mbit/s). The peripheral controller portion of the ISP1161A1 also complies with Universal Serial Bus Specification Rev. 2.0, supporting data transfer at full-speed (12 Mbit/s). These two USB controllers, the controller and peripheral controller, share the same microprocessor bus interface. They have the same data bus, but different I/O locations. They also have separate interrupt request output pins, separate DMA channels that include separate DMA request output pins and DMA acknowledge input pins. This makes it possible for a microprocessor to control both the USB host controller and the USB peripheral controller at the same time.
The ISP1161A1 provides two downstream ports for the USB host controller and one upstream port for the USB peripheral controller. Each downstream port has an overcurrent (OC) detection input pin and power supply switching control output pin. The upstream port has a VBUS detection input pin.The ISP1161A1 also provides separate wake-up input pins and suspended status output pins for the USB host controller and the USB peripheral controller, respectively. This makes power management flexible. The downstream ports for the host controller can be connected with any USB compliant devices and hubs that have USB upstream ports. The upstream port for the peripheral controller can be connected to any USB compliant USB host and USB hubs that have USB downstream ports.
The host controller is adapted from the Open Host Controller Interface Specification for USB Release 1.0a, referred to as OHCI in the rest of this document.
The peripheral controller is compliant with most USB device class specifications such as Imaging Class, Mass Storage Devices, Communication Devices, Printing Devices and Human Interface Devices.
The ISP1161A1 is well suited for embedded systems and portable devices that require a USB host only, a USB peripheral only, or a combination of a configurable USB host and USB peripheral. The ISP1161A1 brings high flexibility to the systems that have it built-in. For example, a system that uses an ISP1161A1 allows it not only to be connected to a PC or USB hub with a USB downstream port, but also to be connected to a device that has a USB upstream port such as a USB printer, USB camera, USB keyboard or a USB mouse. Therefore, the ISP1161A1 enables point-to-point connectivity between embedded systems. An interesting application example is to connect an ISP1161A1 host controller with an ISP1161A1 peripheral controller.
Consider an example of an ISP1161A1 being used in a Digital Still Camera (DSC) design. Figure 1 shows an ISP1161A1 being used as a USB peripheral controller. Figure 2 shows an ISP1161A1 being used as a USB host controller. Figure 3 shows an ISP1161A1 being used as a USB host controller and a USB peripheral controller at the same time.
