net2890 ETC-unknow, net2890 Datasheet - Page 43

• Manufacturer Part Number: net2890
• Description: Interface Controller
• Manufacturer: ETC-unknow

Specification
5.4.2 (Address 11h; EPRSPSET) Endpoint Response Set Register (one per
Endpoint)
NOTE: Writing a 1 to a bit position sets that bit and writing a 0 has no effect.
Bits
____________________________________________________________________________________
7
6
5
4
3
2
1
0
Description
Reserved.
End of Transfer Response. This bit is only used for IN endpoints. If FIFO Valid
Mode is false, setting this bit causes the endpoint to automatically terminate USB
transfers with a zero length packet when necessary. If the last packet sent was full
(Short Packet Transferred is false), and an IN token arrives when the FIFO is empty,
the endpoint returns a zero length packet (instead of NAK) to indicate end of transfer
to the host.
Interrupt Mode.
This bit is only used for INTERRUPT endpoints. For normal interrupt data, this bit
should be set to zero and standard data toggle protocol is followed. When this
interrupt endpoint is used for isochronous rate feedback information, this bit should
be set high. In this mode the data toggle bit is changed after each packet is sent to the
host without regard to handshaking. No packet retries are performed in the rate
feedback mode.
Control Status Phase Handshake. This bit is only used for endpoint 0. This bit is
automatically set when a setup packet is detected. While the bit is set, a control status
phase will be acknowledged with a NAK. Once cleared, the proper response will be
returned to the host (ACK for Control Reads and zero-length packets for Control
Writes).
Receive Handshake Mode. This bit is only used for OUT endpoints. This bit selects
the response if the previous receive packet has not been processed by the local CPU.
If this bit is low, the NET2890 will accept the OUT packet if there is space available
in the endpoint’s FIFO. If this bit is high, the NET2890 will respond to the host with
a NAK if an OUT packet is received and the Data Packet Received Interrupt status
bit is still set from the previous packet.
Reserved.
Endpoint Toggle. This bit is used to set the endpoint data toggle bit. Reading this bit
returns the current state of the endpoint data toggle bit.
Endpoint Stall. This bit is used to set the endpoint stall bit. When an Endpoint Set
Feature Standard Request to the stall bit is detected by the local CPU, it must write a
1 to this bit. Reading this bit returns the current state of the endpoint stall bit.
335 Pioneer Way, Mountain View, California 94041
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NetChip Technology, Inc., 1999
Rev 2.0, Draft 9, July 16, 1999
http://www.netchip.com
NET2890 USB Interface Controller
Read
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Write
No
No
Default
Value
0
1
0
0
1
0
0
0
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