EZ-USB Datasheet, PDF (194/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

12 EZ-USB Registers
12.1 Introduction
This section describes the EZ-USB registers in the order they appear in the EZ-USB mem-
ory map. The registers are named according to the following conventions.
Most registers deal with endpoints. The general register format is DDDnFFF, where:
DDD is endpoint direction, IN or OUT with respect to the USB host.
n is the endpoint number, where:
• “07” refers to endpoints 0-7 as a group.
• 0-7 refers to each individual BULK/INTERRUPT/CONTROL endpoint.
• “ISO” indicates isochronous endpoints as a group.
FFF is the function, where:
• CS is a control and status register
• IRQ is an Interrupt Request bit
• IE is an Interrupt Enable bit
• BC, BCL, and BCH are byte count registers. BC is used for single byte counts,
and BCL/H are used as the low and high bytes of 16-bit byte counts.
• DATA is a single-register access to a FIFO.
• BUF is the start address of a buffer.
Examples:
• IN7BC is the Endpoint 7 IN byte count.
• OUT07IRQ is the register containing interrupt request bits for OUT endpoints 0-7.
• INISOVAL contains valid bits for the isochronous IN endpoints (EP8IN-EP15IN).
EZ-USB TRM v1.9
Chapter 12. EZ-USB Registers
Page 12-1