AN2131QC Cypress Semiconductor Corp, AN2131QC Datasheet - Page 132

• Manufacturer Part Number: AN2131QC
• Description: IC MCU 8051 8K RAM 24MHZ 80BQFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131QC

• 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: 24
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1307

The only Set_Feature/Endpoint request presently defined in the USB Specification is to
stall an endpoint. The 8051 should respond to this request by setting the stall bit in the
Control and Status register for the indicated endpoint EP (byte 4 of the request). The 8051
can either stall an endpoint on its own, or in response to the device request. Endpoint
stalls are cleared by the host Clear_Feature/Stall request.
The 8051 should respond to the Set_Feature/Stall request by performing the following
steps:
Steps 3 and 4 restore the stalled endpoint to its default condition, ready to send or accept
data after the stall condition is removed by the host (using a Clear_Feature/Stall request).
These steps are also required when the host sends a Set_Interface request.
EZ-USB TRM v1.9
Data Toggles
The EZ-USB core automatically maintains the endpoint toggle bits to ensure data integ-
rity for USB transfers. The 8051 should directly manipulate these bits only for a very
limited set of circumstances:
1. Set the stall bit in the indicated endpoint’s CS register.
2. Reset the data toggle for the indicated endpoint.
3. For an IN endpoint, clear the busy bit in the indicated endpoint’s CS register.
4. For an OUT endpoint, load any value into the endpoint’s byte count register.
5. Clear the HSNAK bit in the EP0CS register (by writing 1 to it) to terminate the
•
•
•
Set_Feature/Stall CONTROL transfer.
Set_Feature/Stall
Set_Configuration
Set_Interface
Byte
0
1
2
3
4
5
6
7
bmRequestType
bRequest
wValueL
wValueH
wIndexL
wIndexH
wLengthL
wLengthH
Field
Table 7-7. Set Feature-Endpoint (Stall)
Value
0x02
0x03
0x00
0x00
0x00
0x00
0x00
EP
Chapter 7. EZ-USB CPU
OUT, Endpoint
“Set Feature”
Feature Selector:
STALL
Meaning
Set the STALL bit for the
indicated endpoint:
EP(n):
0x00-0x07: OUT0-OUT7
0x80-0x87: IN0-IN7
8051 Response
Page 7-11