Answers Database
JTAG - Mandatory instructions defined by IEEE standard 1149.1
Record #1174
Problem Title:
JTAG - Mandatory instructions defined by IEEE standard 1149.1
Problem Description:
Urgency: Standard
General Description:
What are the mandatory Boundary Scan instructions defined by the
IEEE 1149.1 standard?
Solution 1:
The only JTAG instructions which are defined and required
by the IEEE 1149.1 standard are BYPASS, EXTEST and
SAMPLE/PRELOAD.
BYPASS is defined as all bits in the IR as all ones.
EXTEST is defined as all bits in the IR as all zeros.
The standard has not designated a mandatory bit pattern for the
SAMPLE/PRELOAD instruction . This is controlled by the IC
manufacturer.
All other JTAG instructions are defined by the IC manufacturer and
can be found in the BSDL file or in the data sheets
End of Record #1174 - Last Modified: 01/10/00 22:07 |
