Eight-Bit MCU Integrates USB-To-Serial Bridge

Usable with standard operating systems for host-peripheral communications, the AT76C713 commandeers position as the first 8-bit, 48-MHz microcontroller to include USB-to-serial bridging capabilities. The device provides a full-speed USB slave interface, compliant to USB 2.0, to systems that need to communicate with a peripheral as a standard or custom-class USB device. Its memory architecture includes 16 KB of SRAM for program code and four SRAM banks of 2 KB each for data, stack, and variables. Up to three banks are deployable as program memory in addition to the default 16 KB. Additional memory includes a USB Chapter 9-compliant bootstrap ROM that supports enumeration and program downloads using descriptor parameters stored in an external EEPROM, data flash or hard-wired. Other on-board features include an array of GPIO pins with multifunction capabilities such as data-memory interfaces, input-interrupt lines, output-compare timers, or modem-control signals for the serial links, supported by two internal UART modules. The UART modules support FIFOs in both directions; one UART supports IrDA communication. Price for the AT76C713 is $4 each/10,000. A development kit (AT76C713-DK) is also available with sample programs, utilities for program downloading, and a firmware upgrade. ATMEL CORP., San Jose, CA. (408) 441-0311.