Five control signals (DCUTCK, DCUTDI, DCUTDO, DCUTMS, and DCUTRST)
TAP controller
Instruction register
Bypass register
Boundary scan register
The JTAG interface has four instructions.
BYPASS
Test mode conforming to the IEEE 1149.1
EXTEST
Test mode conforming to the IEEE 1149.1
SAMPLE/PRELOAD
Test mode conforming to the IEEE 1149.1
IDCODE
Test mode conforming to the IEEE 1149.1