AN2131SC Cypress Semiconductor Corp, AN2131SC Datasheet - Page 26

• Manufacturer Part Number: AN2131SC
• Description: IC MCU 8051 8K RAM 24MHZ 44QFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131SC

• Applications: USB Microcontroller
• Core Processor: 8051
• Program Memory Type: ROMless
• Controller Series: AN213x
• Ram Size: 8K x 8
• Interface: I²C, USB
• Number Of I /o: 16
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1306; AN2131SC

Control transfers consist of two or three stages. The SETUP stage contains eight bytes of
USB CONTROL data. An optional DATA stage contains more data, if required. The
STATUS (or handshake) stage allows the device to indicate successful completion of a
control operation.
Your computer is ON. You plug in a USB device, and the Windows
an hourglass, and then back to a cursor. And magically, your device is connected and its
Windows
configure countless jumpers, drivers, and IO/Interrupt/DMA settings knows that a USB
connection can be like a miracle. We’ve all heard about Plug and Play, but USB delivers
the real thing.
How does all this happen automatically? Inside every USB device is a table of ‘descrip-
tors’ that are the sum total of the device’s requirements and capabilities. When you plug
into USB, the host goes through a ‘sign-on’ sequence:
This sign-on process is called Enumeration.
EZ-USB TRM v1.9
1.9
1. The host sends a “Get_Descriptor/Device” request to address zero (devices must
2. The device dutifully responds to this request by sending ID data back to the host
3. The host sends the device a “Set_Address” request, which gives it a unique address
4. The host sends more “Get_Descriptor” requests, asking more device information.
respond to address zero when first attached).
telling what it is.
to distinguish it from the other devices connected to the bus.
from this, it learns everything else about the device, like how many endpoints the
device has, its power requirements, what bus bandwidth it requires, and what
driver to load.
Enumeration
driver is loaded! Anyone who has installed a sound card into a PC and had to
Chapter 1. Introducing EZ-USB
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