mc68hc908jb8 Freescale Semiconductor, Inc, mc68hc908jb8 Datasheet - Page 142

• Manufacturer Part Number: mc68hc908jb8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Universal Serial Bus Module (USB)
Technical Data
142
RXD2F — Endpoint 2 Data Receive Flag
TXD1F — Endpoint 1 Data Transmit Flag
RESUMF — Resume Flag
To enable the next data packet transmission, TX2E also must be set.
If the TXD2F bit is not cleared, a NAK handshake will be returned in
the next IN transaction.
Reset clears this bit. Writing to TXD2F has no effect.
This read-only bit is set after the USB 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 RXD2FR bit after all of
the received data has been read. Software also must set the RX2E bit
to 1 to enable the next data packet reception. If the RXD2F bit is not
cleared, a NAK handshake will be returned in the next OUT
transaction.
Reset clears this bit. Writing to RXD2F has no effect.
This read-only bit is set after the data stored in the endpoint 1 transmit
buffer 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 TXD1FR bit. To
enable the next data packet transmission, TX1E also must be set. If
the TXD1F bit is not cleared, a NAK handshake will be returned in the
next IN transaction.
Reset clears this bit. Writing to TXD1F has no effect.
This read-only bit is set when USB bus activity is detected while the
SUSPND bit is set. Software must clear this flag by writing a logic 1 to
the RESUMFR bit. Reset clears this bit. Writing a logic 0 to RESUMF
has no effect.
1 = Transmit on endpoint 2 has occurred
0 = Transmit on endpoint 2 has not occurred
1 = Receive on endpoint 2 has occurred
0 = Receive on endpoint 2 has not occurred
1 = Transmit on endpoint 1has occurred
0 = Transmit on endpoint 1has not occurred
1 = USB bus activity has been detected
0 = No USB bus activity has been detected
Universal Serial Bus Module (USB)
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
Freescale Semiconductor