Test access port (TAP)
Definition
The set of four or five contact pads (TDI, TDO, TCK, TMS, and optionally TRST) on a circuit board that implement the IEEE 1149.1 boundary-scan interface. These are the connection points for JTAG acquisition hardware.
Related terms
- Chip-off acquisition
- A physical extraction method in which the flash memory chip is desoldered from the device's circuit board and read directly with specialised...
- eMMC (embedded MultiMediaCard)
- A flash storage standard that packages NAND memory chips and a controller into one soldered module using a parallel interface. Common in...
- ISP (In-System Programming)
- A variant of direct chip access that connects to the eMMC command and data pins while the chip is still on the...
- JTAG (Joint Test Action Group)
- The industry group that produced IEEE standard 1149.1, which defines the test access port and boundary-scan architecture built into most modern integrated...
- Pinout
- A diagram or database entry that maps each physical contact on a device's circuit board to its signal function. For JTAG acquisition,...
Explained in
- JTAG and Chip-Off AcquisitionThe set of four or five contact pads (TDI, TDO, TCK, TMS, and optionally TRST) on a circuit board that implement the IEEE 1149.1 boundary-scan interface. These...