Keyword: TWR, Timing Analyzer, TRCE, Tshcko, RAM, report
Below is a snippet of a timing report (.twr/.twx) file:
What does the "Twos" symbol mean?
The Twos symbol is the same as Tshcko16, Tshcko32, or Treg in the data sheet. See the Virtex-E data sheet: http://www.xilinx.com/support/documentation/virtex-e_data_sheets.htm.
"Tshcko16/32" denotes clock-to-out of Distributed RAM during a WRITE command. "Treg" denotes clock-to-out of a shift register (SRL16).
The Twos value can vary depending on the output path of the RAM or SRL.
For example, the delay of the RAM output going directly to the X/Y output pin of the slice is different from the delay of the same RAM going to MUXF5 before being output to the slice's X/Y pin.