Information

Power-on reset
TMS
TCK
TDI
1-bit Bypass Register
32-bit Device Identification Register
Boundary Scan Register
TAP Instruction Decoder
TAP Instruction Register
TDO
Test Access Port (TAP)
Controller
Figure 49-1. JTAG (IEEE 1149.1) block diagram
49.1.2 Features
The JTAGC block is compliant with the IEEE 1149.1-2001 standard, and supports the
following features:
• IEEE 1149.1-2001 Test Access Port (TAP) interface
• 4 pins (TDI, TMS, TCK, and TDO)
• Instruction register that supports several IEEE 1149.1-2001 defined instructions as
well as several public and private device-specific instructions. Refer to Table 49-3
for a list of supported instructions.
• Bypass register, boundary scan register, and device identification register.
• TAP controller state machine that controls the operation of the data registers,
instruction register and associated circuitry.
49.1.3 Modes of operation
The JTAGC block uses a power-on reset indication as its primary reset signals. Several
IEEE 1149.1-2001 defined test modes are supported, as well as a bypass mode.
Introduction
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
1216 Freescale Semiconductor, Inc.