Serial Vector Format Specification
ASSET INTERTECH, INC. V 10 MARCH 1999
INTRODUCTION
This document describes the syntax for a Serial Vector Format (SVF) file. SVF is
the media for exchanging descriptions of high-level IEEE 1149.1 bus operations.
In general, IEEE 1149.1 bus operations consist of scan operations and
movements between different stable states on the IEEE 1149.1 state diagram.
SVF does not explicitly describe the state of the IEEE 1149.1 bus at every Test
Clock.
SVF is designed to encourage reuse of serial vectors throughout the life cycle of
the product, from its inception in the design phase to its deployment in the field
service phase, and all phases in between. Life-cycle portability places
restrictions on the design and capabilities of SVF.
The SVF file is defined as an ASCII file that consists of a set of SVF statements.
The maximum number of characters allowed on a line is 256, although one SVF
statement can span more than one line. Each statement consists of a command
and associated parameters. Each SVF statement is terminated by a semicolon.
SVF is not case sensitive. Comments can be inserted into a SVF file after an
exclamation point ‘!’ or a pair of slashes ‘//’. Either ‘//’ or ‘!’ will comment out the
remainder of the line.
Scan data within a statement is expressed as hexadecimal and is always
enclosed in parentheses. The scan data cannot specify a data string that is
larger than the specified bit length. Most Significant Bit (MSB) zeroes in the hex
string are not considered when determining if the string is too large. The bit
order for scan data follows the convention that the least significant bit (rightmost
bit) is the first bit scanned into the hardware for TDI and SMASK scan data and
is the first bit scanned out for TDO and MASK data. This bit ordering is
consistent with the IEEE 1149.1 convention.
An example of an SVF file is:
!Begin Test Program
TRST OFF; !Disable Test Reset line
ENDIR IDLE; !End IR scans in IDLE
ENDDR IDLE; !End DR scans in IDLE
HIR 8 TDI (00); !8-bit IR header
HDR 16 TDI (FFFF) TDO (FFFF) MASK (FFFF);!16-bit DR header
TIR 16 TDI (0000); !16-bit IR trailer
TDR 8 TDI (12); !16-bit DR trailer
SIR 8 TDI (41); !8-bit IR scan
SDR 32 TDI (ABCD1234) TDO (11112222); !32-bit DR scan
STATE DRPAUSE; !Go to stable state DRPAUSE
RUNTEST 100 TCK ENDSTATE IRPAUSE; !RUNBIST for 100 TCKs
!End Test Program
