at85c51snd3 ATMEL Corporation, at85c51snd3 Datasheet - Page 134

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

“Autoswitch” Mode
CRC Error (isochronous only)
Interrupt
134
AT85C51SND3B
In this mode, the clear of the FIFOCON bit is performed automatically by hardware each
time the Pipe bank is empty. The firmware has to check if the next bank is empty or not
before reading the next data. On RXIN interrupt, the firmware reads a complete bank. A
new interrupt will be generated each time the current bank contains data to read.
The acknowledge of the RXIN interrupt is always performed by software.
A CRC error can occur during IN stage if the USB controller detects a bad received
packet. In this situation, the STALLEDI/CRCERRI interrupt is triggered. This does not
prevent the RXINI interrupt from being triggered.
Figure 67 shows all the host interrupts sources while Figure 68 details the pipe interrupt
sources.
Figure 67. USB Host Controller Interrupt System
DCONNI
RXRSMI
RSMEDI
HWUPI
DDISCI
UHINT.6
HSOFI
UHINT.5
UHINT.4
UHINT.3
UHINT.2
UHINT.1
UHINT.0
RSTI
RXRSME
DCONNE
HWUPE
UHIEN.6
UDIEN.4
UHIEN.2
UHIEN.0
RSTE
RSMEDE
DDISCE
HSOFE
UHIEN.5
UHIEN.3
UHIEN.1
USB Host
Interrupt
7632D–MP3–01/07