AN21XX

The Anchor Chips EZ-USB™ family (AN21XX/AN23XX) provides significant improvements over other USB architectures including an enhanced 8051 core, 4 or 8 Kbytes of RAM, an intelligent USB core, and high-performance I/O ports. The family includes 16 different products to accommodate the needs of different systems.

The enhanced 8051 core provides five times the performance of the standard 8051, while maintaining complete 8051 software compatibility. With on-chip RAM, firmware code can be downloaded from the host PC. This allows the peripheral manufacturer to easily modify and transfer new code to current and new users. This on-chip memory eliminates the need for external memory.

The EZ-USB family supports high-bandwidth transfers by providing an efficient mechanism to move data between external memory and the USB FIFOs. Using this "turbo mode," the 8051 core can transfer 1024 bytes of data in or out of an isochronous FIFO in 338 microseconds.This leaves a high percentage of the bandwidth for the processor to service the application. The EZ-USB family also supports an equivalent data transfer rate for bulk packets of over 2 Mbytes per second, which is more than the USB bandwidth.

The EZ-USB family conforms to the high-speed (12 Mbps) requirements of USB Specification version 1.0, including support for remote wake-up. The internal SRAM replaces Flash memory, EEPROM,
EPROM, or masked ROM that is conventionally used in other USB
solutions.

The EZ-USB family offers two packages, a 44 PQFP and an 80 PQFP. All EZ-USB devices are pin- and software-compatible. And, all RAM versions have ROM equivalents to allow easy migration for highvolume applications.