Features: • AVR Microcontroller
• Clock Generator Provides CPU Rates up to 24 MHz
• Programmable UART with 16-byte FIFOs at the Receiver Side (1), with a Maximum Rate of 921K Baud
• Programmable SPI Interface
• Full-speed USB Function Controller
• On-chip 2K Bytes SRAM (for Data)
• On-chip 2K Bytes Dual-port RAM for Segmentation and Reassembly of Packets Exchanged between the USB and the UART Interfaces
• 8K x 16-bit In-system SRAM for Program Code
• On-chip Bootstrap ROM for Program Uploading to the Internal Program SRAM, Either from the USB or the SPI
• One USB Control Endpoint
• Five USB Programmable Endpoints (up to 64 Bytes) with Double-buffered FIFOs for Back-to-back Transfers
• One 8-bit Timer/Counter
• One 16-bit Timer/Counter
• External and Internal Interrupt Sources
• Programmable Watchdog Timer
• Independent UART BRG Oscillator
• 64-pin TQFP Package
• 3.3V OperationApplicationAT76C711 can be used in applications where peripheralssupporting fast serial asynchronous or synchronous trans-fer of data have to communicate with a host or otherperipherals through a high-speed serial link, like USB.Typical areas of AT76C711 usage are:• Connection of Network Interface Cards (NICs) to a host system• Wireless communications• Bridging of microcontrollers with different types of serial interfaces• USB to UART bridge• USB to IrDA bridge• IrDA to UART bridge• Packet adaptation of network protocol packets to USB requirements
Pinout
DescriptionThe Atmel AT76C711 is a compound USB device designedto provide a high-speed USB interface to devices that needto communicate with a base station through fast seriallinks, like UARTs and IrDA interfaces. It is based on theAVR-enhanced RISC architecture and consists of a USBfunction interface with a devoted DMA controller for fasttransfers of data between the endpoint FIFOs and theDPRAM, a 2 KB internal RAM, a Synchronous PeripheralInterface (SPI), a UART, supporting a maximum rate of921K baud, an 8K x 16-bit in-system SRAM for microcodestorage, which is loaded from the SPI controller, 2K bytesdual-port RAM (DPRAM) and a programmable DMA con-troller for packet transfers between the UART and theDPRAM, without microcontroller intervention. An IrDA con-troller is also provided, attached to a second UART moduleand is able to communicate with an IrDA transceiver with amaximum rate of 1.2 Mbps. A hardwired Device FirmwareUpgrade (DFU) protocol handler is implemented for pro-gramming an external AT76C711 serial Flash during theproduction phase. An internal bootstrap ROM contains theexecutable program for uploading the application codefrom an external serial Flash to the on-chip programSRAM. Alternatively, microcode can be stored in the pro-gram SRAM using the slave program mode while the chipis in the reset state. The USB and peripheral device AT76C711 con-troller function should be implemented in themicrocontroller's firmware.
The device AT76C711 is suitable for applications where minimizationof power dissipation is required, since there are no power-consumable transactions with external parallel devices.The USB H/W block consists of a USB transceiver, the SIE,endpoint controllers and an interface to the microcontroller.
The USB H/W AT76C711 interfaces to the USB host at the packetlevel. The microcontroller firmware handles the higher-levelUSB protocol layers that are not processed by the USBH/W and in addition, it performs the peripheral controlfunctions.A typical application of AT76C711 and its functional dia-gram are shown in Figures 2 and 3.
AT76C711 Data Sheet
