The HPI-USB has a maximum data rate of 400KBytes per second. It's
compatible with any ZSP development or evaluation board with a 34-pin HPI
connector. Power is supplied by the target board. The HPI-USB can operate in
either 16 or 8-bit transfer mode. The host port is monitored and serviced by
the 25MHz, single cycle 8051 micro-controller. The USB data transfer is
available directly through the FTDI interface DLL. A sample host application is
provided. Commands and functions supported by the micro-controller are
described in the comprehensive online help file: ZSPHOSTusb.chm.