Rainbow Electronics AT91CAP9S250A User Manual

Page 900

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6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

• ERR_OVFLW: Overflow Error

This bit is set by hardware when a new too-long packet is received.

Example: If the user programs an endpoint 64 bytes wide and the host sends 128 bytes in an OUT transfer, then the Over-
flow Error bit is set.

This bit is updated at the same time as the BYTE_COUNT field.

This bit is reset by UDPHS_EPTRST register EPT_x (reset endpoint) and by UDPHS_EPTCTLDISx (disable endpoint).

• RX_BK_RDY/KILL_BANK: Received OUT Data/KILL Bank

Received OUT Data: (For OUT endpoint or Control endpoint)

This bit is set by hardware after a new packet has been stored in the endpoint FIFO.

This bit is cleared by the device firmware after reading the OUT data from the endpoint.

For multi-bank endpoints, this bit may remain active even when cleared by the device firmware, this if an other packet has
been received meanwhile.

Hardware assertion of this bit may generate an interrupt if enabled by the UDPHS_EPTCTLx register RX_BK_RDY bit.

This bit is reset by UDPHS_EPTRST register EPT_x (reset endpoint) and by UDPHS_EPTCTLDISx (disable endpoint).

KILL Bank: (For IN endpoint)

– the bank is really cleared or the bank is sent, BUSY_BANK_STA is decremented.

– the bank is not cleared but sent on the IN transfer, TX_COMPLT

– the bank is not cleared because it was empty. The user should wait that this bit is cleared before trying to clear

another packet.

Note: “Kill a packet” may be refused if at the same time, an IN token is coming and the current packet is sent on the
UDPHS line. In this case, the TX_COMPLT bit is set. Take notice however, that if at least two banks are ready to be sent,
there is no problem to kill a packet even if an IN token is coming. In fact, in that case, the current bank is sent (IN transfer)
and the last bank is killed.

• TX_COMPLT: Transmitted IN Data Complete

This bit is set by hardware after an IN packet has been transmitted for isochronous endpoints and after it has been
accepted (ACK’ed) by the host for Control, Bulk and Interrupt endpoints.

This bit is reset by UDPHS_EPTRST register EPT_x (reset endpoint), and by UDPHS_EPTCTLDISx (disable endpoint).

• TX_PK_RDY/ERR_TRANS: TX Packet Ready/Transaction Error

TX Packet Ready:

This bit is cleared by hardware, as soon as the packet has been sent for isochronous endpoints, or after the host has
acknowledged the packet for Control, Bulk and Interrupt endpoints.

For Multi-bank endpoints, this bit may remain clear even after software is set if another bank is available to transmit.

Hardware clear of this bit may generate an interrupt if enabled by the UDPHS_EPTCTLx register TX_PK_RDY bit.

This bit is reset by UDPHS_EPTRST register EPT_x (reset endpoint), and by UDPHS_EPTCTLDISx (disable endpoint).

Transaction Error: (For high bandwidth isochronous OUT endpoints) (Read-Only)

This bit is set by hardware when a transaction error occurs inside one microframe.

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