SX2 does not support the low-speed signaling rate of 1.5 Mbits/sec.
However, Cypress offers low-speed USB microcontrollers that provide powerful, flexible, integrated solutions for a wide range of USB applications. The devices feature the 8-bit RISC core with RAM, OTP PROM, USB logic, and a USB transceiver all integrated into a single device. Please point your browser to "http://www.cypress.com".
(1) Click on the "Products" tab.
(2) Click on "USB Low Speed Peripherals" under the listing of "USB Controllers".
(3) Click on the part number to download its datasheet.