MC908JB12DWE Datasheet, PDF (189/332 Pages) Freescale Semiconductor, Inc – MC68HC908JB16 Technical Data

Universal Serial Bus Module (USB)
11.8.5 USB Control Register 0
Address: $003B
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
T0SEQ
Write:
TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0
Reset: 0
0
0
0
0
0
0
0
Figure 11-19. USB Control Register 0 (UCR0)
T0SEQ — Endpoint 0 Transmit Sequence Bit
This read/write bit determines which type of data packet (DATA0 or
DATA1) will be sent during the next IN transaction directed at
endpoint 0. Toggling of this bit must be controlled by software. Reset
clears this bit.
1 = DATA1 token active for next endpoint 0 transmit
0 = DATA0 token active for next endpoint 0 transmit
TX0E — Endpoint 0 Transmit Enable
This read/write bit enables a transmit to occur when the USB host
controller sends an IN token to endpoint 0. Software should set this
bit when data is ready to be transmitted. It must be cleared by
software when no more endpoint 0 data needs to be transmitted.
If this bit is 0 or the TXD0F is set, the USB will respond with a NAK
handshake to any endpoint 0 IN tokens. Reset clears this bit.
1 = Data is ready to be sent
0 = Data is not ready. Respond with NAK
RX0E — Endpoint 0 Receive Enable
This read/write bit enables a receive to occur when the USB host
controller sends an OUT token to endpoint 0. Software should set this
bit when data is ready to be received. It must be cleared by software
when data cannot be received.
If this bit is 0 or the RXD0F is set, the USB will respond with a NAK
handshake to any endpoint 0 OUT tokens; but does not respond to a
SETUP token. Reset clears this bit.
1 = Data is ready to be received
0 = Not ready for data. Respond with NAK
MC68HC908JB16 — Rev. 1.1
Freescale Semiconductor
Universal Serial Bus Module (USB)
Technical Data
189