at85c51snd3 ATMEL Corporation, at85c51snd3 Datasheet - Page 129

• Manufacturer Part Number: at85c51snd3
• Description: At85c51snd3 Single-chip Digital Audio Decoder - Encoder With Usb 2.0 Interface
• Manufacturer: ATMEL Corporation

Pipe Configuration
7632D–MP3–01/07
The following flow must be respected in order to activate a Pipe:
Figure 66. Pipe activation flow:
Once the Pipe is activated (EPEN set) and, the hardware is ready to send requests to
the Device.
When configured (CFGOK = 1), only the Pipe Token (PTOKEN) and the polling interval
for Interrupt pipe can be modified.
A Control type pipe supports only 1 bank. Any other value will lead to a configuration
error (CFGOK = 0).
A clear of PEN will reset the configuration of the Pipe. All the corresponding Pipe regis-
ters are reset to there reset values. Please refers to the Memory Management chapter
for more details.
Note:
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The firmware asks for 8 bytes of the Device Descriptor sending a GET_DESCRIPTOR
request. These bytes contains the MaxPacketSize of the Device default control endpoint
and the firmware re-configures the size of the Default Control Pipe with this size
parameter.
Type: Control
Token: SETUP
Data bank: 1
Size: 64 Bytes
The firmware has to configure the Default Control Pipe with the following parameters:
Pipe activ ated
Y es
and f reezed
(interrupt only)
Activ ation
UPCFG0X
UPCFG1X
CFGOK=1
UPCFG2X
PENABLE=1
UPCONX
PEPNUM
CFGMEM
PT OKEN
INT FRQ
PTYPE
Pipe
PSIZE
PBK
Configure the polling interval
for Interrupt pipe
Select the Pipe type:
* Type (Control, Bulk, Interrupt)
* Token (IN, OUT , SET UP)
* Endpoint number
Configure the Pipe memory:
* Pipe size
* Number of banks
No
Enable the pipe
ERROR
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