MC68HC908LD64 Datasheet, PDF (205/362 Pages) Freescale Semiconductor, Inc – Microcontrollers

Universal Serial Bus Module (USB)
Hub Function I/O Registers
14.6.7 USB Hub Control Register 0 (HCR0)
Address: $005B
Bit 7
6
5
4
3
2
1
Read:
TSEQ STALL0 TXE
Write:
RXE TPSIZ3 TPSIZ2 TPSIZ1
Reset: 0
0
0
0
0
0
0
Figure 14-9. USB Hub Control Register 0 (HCR0)
Bit 0
TPSIZ0
0
TSEQ — Hub 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 hub endpoint 0 transmit
0 = DATA0 token active for next hub endpoint 0 transmit
STALL0 — Hub Endpoint 0 Force Stall Bit
This read/write bit causes hub endpoint 0 to return a STALL
handshake when polled by either an IN or OUT token by the host. The
USB hardware clears this bit when a SETUP token is received. Reset
clears this bit.
1 = Send STALL handshake
0 = Default
TXE — Hub Endpoint 0 Transmit Enable
This read/write bit enables a transmit to occur when the USB host
controller sends an IN token to the hub endpoint 0. Software should
set this bit when data is ready to be transmitted. It must be cleared by
software when no more hub endpoint 0 data packets needs to be
transmitted. If this bit is 0 or the TXDF is set, the USB will respond with
a NAK handshake to any hub endpoint 0 IN tokens. Reset clears this
bit.
1 = Data is ready to be sent
0 = Data is not ready; respond with NAK
MC68HC908LD64 — Rev. 3.0
Freescale Semiconductor
Universal Serial Bus Module (USB)
Data Sheet
205