AN2131-DK001 Cypress Semiconductor Corp, AN2131-DK001 Datasheet - Page 226

• Manufacturer Part Number: AN2131-DK001
• Description: KIT EZ-USB DEVELOPMENT BOARD
• Manufacturer: Cypress Semiconductor Corp

Specifications of AN2131-DK001

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1333

Bit 0:
The 8051 sets this bit to “1” to stall an endpoint, and to “0” to clear a stall.
When the stall bit is “1,” the EZ-USB core returns a STALL Handshake for all requests to
the endpoint. This notifies the host that something unexpected has happened.
The 8051 sets an endpoint’s stall bit under two circumstances:
The 8051 clears an endpoint’s stall bit under two circumstances:
All stall bits are automatically cleared when the EZ-USB chip ReNumerates
the DISCON bit HI.
EZ-USB TRM v1.9
1. The host sends a “Set_Feature—Endpoint Stall” request to the specific endpoint.
2. The 8051 encounters any show stopper error on the endpoint, and sets the stall bit
1. The host sends a “Clear_Feature--Endpoint Stall” request to the specific endpoint.
2. The 8051 receives some other indication from the host that the stall should be
to tell the host to halt traffic to the endpoint.
cleared (this is referred to as “host intervention” in the USB Specification). This
indication could be a USB bus reset.
INnSTL
IN Endpoint (1-7) Stall
Chapter 12. EZ-USB Registers
by pulsing
Page 12-33