Length and Width

LREF, WREF
In HSPICE these are ``channel length reference'' and ``channel width reference''. There are no WRspice equivalents.

XW, XL
In HSPICE these account for masking and etching effects. In release 3.1.5 and later, the XW and XL parameters are handled by the BSIM3 bulk-mos models (levels 7, 8, 9, 47, 49, and 53) implementing the formula below. With earlier releases, one must modify WINT and LINT.

WINT_new = WINT_old - XW /2
LINT_new = LINT_old - XL /2