MC68HC(7)08KH12Rev. 1.1 Advance Information
Freescale Semiconductor 139
TXD0F — Embedded Device Endpoint 0 Data Transmit Flag
This read only bit is set after the data stored in embedded device
Endpoint 0 transmit buffers has been sent and an ACK handshake
packet from the host is received. Once the next set of data is ready in
the transmit buffers, software must clear this flag by writing a logic 1
to the TXD0FR bit. To enable the next data packet transmission,
TX0E must also be set. If TXD0F bit is not cleared, a NAK handshake
will be returned in the next IN transaction. Reset clears this bit. Writing
to TXD0F has no effect.
1 = Transmit on embedded device Endpoint 0 has occurred
0 = Transmit on embedded device Endpoint 0 has not occurred
RXD0F — Embedded Device Endpoint 0 Data Receive Flag
This read only bit is set after the USB embedded device module has
received a data packet and responded with an ACK handshake
packet. Software must clear this flag by writing a logic 1 to the
RXD0FR bit after all of the received data has been read. Software
must also set RX0E bit to one to enable the next data packet
reception. If RXD0F bit is not cleared, a NAK handshake will be
returned in the next OUT transaction.
Reset clears this bit. Writing to RXD0F has no effect.
1 = Receive on embedded device Endpoint 0 has occurred
0 = Receive on embedded device Endpoint 0 has not occurred
TXD0IE — Embedded Device Endpoint 0 Transmit Interrupt Enable
This read/write bit enables the Transmit Embedded Device Endpoint
0 to generate CPU interrupt requests when the TXD0F bit becomes
set. Reset clears the TXD0IE bit.
1 = Transmit Embedded Device Endpoint 0 can generate a CPU
interrupt request
0 = Transmit Embedded Device Endpoint 0 cannot generate a
CPU interrupt request
RXD0IE — Embedded Device Endpoint 0 Receive Interrupt Enable
This read/write bit enables the Receive Embedded Device Endpoint 0
to generate CPU interrupt requests when the RXD0F bit becomes set.
Reset clears the RXD0IE bit.