diff options
Diffstat (limited to 'decoders/usb/usb.py')
| -rw-r--r-- | decoders/usb/usb.py | 22 |
1 files changed, 1 insertions, 21 deletions
diff --git a/decoders/usb/usb.py b/decoders/usb/usb.py index b209aa3..99dd4b5 100644 --- a/decoders/usb/usb.py +++ b/decoders/usb/usb.py @@ -18,27 +18,7 @@ ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA ## -# -# USB Full-speed protocol decoder -# -# Full-speed USB signalling consists of two signal lines, both driven at 3.3V -# logic levels. The signals are DP (D+) and DM (D-), and normally operate in -# differential mode. -# The state where DP=1,DM=0 is J, the state DP=0,DM=1 is K. -# A state SE0 is defined where DP=DM=0. This common mode signal is used to -# signal a reset or end of packet. -# -# Data transmitted on the USB is encoded with NRZI. A transition from J to K -# or vice-versa indicates a logic 0, while no transition indicates a logic 1. -# If 6 ones are transmitted consecutively, a zero is inserted to force a -# transition. This is known as bit stuffing. Data is transferred at a rate -# of 12Mbit/s. The SE0 transmitted to signal an end-of-packet is two bit -# intervals long. -# -# Details: -# https://en.wikipedia.org/wiki/USB -# http://www.usb.org/developers/docs/ -# +# USB (full-speed) protocol decoder import sigrokdecode as srd |