Cypress AN2121SC 제품 설명서 - 페이지 5

{카테고리_이름} Cypress AN2121SC에 대한 제품 설명서을 온라인으로 검색하거나 PDF를 다운로드하세요. Cypress AN2121SC 16 페이지. Ez-usb series 2100 usb controller

Enumeration and

ReNumeration

Anchor Chips' proprietary

ReNumeration™ function is the

means by which the enhanced

8051 firmware is downloaded.

How It Works

Upon power-up or plug-in, the

EZ-USB chip automatically

enumerates as a default USB

device. This allows the USB core

to download 8051 code. The USB

core logic inside EZ-USB per-

forms this initial enumeration

and code download while holding

the 8051 in reset.

Once enumerated, the host PC

downloads 8051 code into

EZ-USB RAM over the USB

interface. (Anchor Chips supplies

the software tools to incorporate

the loader into any application).

The downloaded 8051 code

contains program, data, and

EZ-USB Series 2100

enumeration tables. Once loaded,

the EZ-USB core performs a

ReNumeration cycle to simulate a

USB disconnect and reconnect to

come back as a completely new

USB device.

This entire sequence of enumera-

tion, download and ReNum-

eration happens quickly (less

than a quarter of a second) and is

transparent to the user.