Clear to free the current bank and to switch to the following bank. Setting by software has no
effect.
• 6 - NAKEDI - NAK Handshake received
Set by hardware when a NAK has been received on the current bank of the Pipe. This triggers
an interrupt if the NAKEDE bit is set in the UPIENX register.
Shall be clear to handshake the interrupt. Setting by software has no effect.
• 5 - RWAL - Read/Write Allowed
OUT Pipe:
Set by hardware when the firmware can write a new data into the Pipe FIFO.
Cleared by hardware when the current Pipe FIFO is full.
IN Pipe:
Set by hardware when the firmware can read a new data into the Pipe FIFO.
Cleared by hardware when the current Pipe FIFO is empty.
This bit is also cleared by hardware when the RXSTALL or the PERR bit is set
• 4 - PERRI -PIPE Error
Set by hardware when an error occurs on the current bank of the Pipe. This triggers an interrupt
if the PERRE bit is set in the UPIENX register. Refers to the UPERRX register to determine the
source of the error.
Automatically cleared by hardware when the error source bit is cleared.
• 3 - TXSTPI - SETUP Bank ready
Set by hardware when the current SETUP bank is free and can be filled. This triggers an inter-
rupt if the TXSTPE bit is set in the UPIENX register.
Shall be cleared to handshake the interrupt. Setting by software has no effect.
• 2 - TXOUTI -OUT Bank ready
Set by hardware when the current OUT bank is free and can be filled. This triggers an interrupt if
the TXOUTE bit is set in the UPIENX register.
Shall be cleared to handshake the interrupt. Setting by software has no effect.
• 1 - RXSTALLI / CRCERR - STALL Received / Isochronous CRC Error
Set by hardware when a STALL handshake has been received on the current bank of the Pipe.
The Pipe is automatically frozen. This triggers an interrupt if the RXSTALLE bit is set in the UPI-
ENX register.
Shall be cleared to handshake the interrupt. Setting by software has no effect.
For Isochronous Pipe:
Set by hardware when a CRC error occurs on the current bank of the Pipe. This triggers an inter-
rupt if the TXSTPE bit is set in the UPIENX register.
Shall be cleared to handshake the interrupt. Setting by software has no effect.
• 0 - RXINI - IN Data received
310
AT90USB64/128
7593A–AVR–02/06
ATMEL [ ATMEL ]
