Packing a 16-bit RISC processor core into a USB controller eliminates many memory and processor performance limitations and keeps power consumption low. This lets the controllers handle more of the USB processing chores. It's possible to have a single-chip solution when the on-chip processor can handle external peripheral management with Cypress Semiconductor's EZ-Host CY7C67300 and EZ-OTG Y7C-67200 embedded host family.
The EZ-Host suits fixed devices, like set-top boxes, wireless access points, and automotive environments. The chip complies with the USB 2.0 standard. It sports a pair of 12-Mbit/s USB SIEs (serial interface engines). Each independent SIE has a pair of USB ports that can be configured in an upstream/downstream mode or a master-to-master mode for linking a pair of PCs.
The EZ-Host has an 8-kbyte ROM BIOS and 16 kbytes of on-chip RAM. An external interface handles SDRAM, SRAM, and flash memory. The I2C can be attached to a small, serial EEPROM for downloading an application when the chip is operating in standalone mode. The BIOS allows the chip to be easily interfaced to an external host.
The EZ-OTG handles the new On-The-Go USB standard, which targets mobile applications like digital cameras and cell phones. It has two SIEs, but each has only a single USB port. The EZ-Host is available in a 100-pin TQFP for $4.99. The EZ-OTG, which comes in a 48-ball FBGA, costs $3.99.
Cypress Semiconductor Inc. • www.cypress.com