NEC UPD98413 User Manual page 316

CHAPTER 6 JTAG BOUNDARY SCAN
6.7.1 BYPASS Instruction
This instruction is specified by instruction data "11" or "10". This instruction is used to select only the bypass register
(to access between the JDI and JDO pins serially) in the Shift-DR controller state.
While this instruction is selected, the operation of the JTAG boundary scan circuit does not affect the operation of the
mPD98414.
This bypass instruction is selected while the TAP controller is in the Test-Logic-Reset state.
6.7.2 EXTEST Instruction
This instruction is specified by instruction data "00". In the Shift-DR controller state, this instruction is used to select
the boundary scan register of serial access between the JDI and JDO instructions.
• While this instruction is selected:
The states of all the signals driven from the system output pins are completely defined by the data shifted to the
boundary scan register. In the Update-DR controller state, the states of all the signals are changed only by the falling
edge of the JCK pin signal.
The states of all the signals input from the system input pins are loaded to the boundary scan register at the rising
edge of the JCK pin signal while the TAP controller is in the Capture-DR state.
6.7.3 SAMPLE/PRELOAD Instruction
This instruction is specified by instruction data "01". This instruction can execute two functions, SAMPLE and
PRELOAD, with a single instruction.
6.7.4 Boundary Scan Data Bit Definition
NEC can supply the BSDL (Boundary Scan Description Language) file for the mPD98414 upon request.
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