Jtag Block Diagram; Features - Motorola ColdFire MCF5281 User Manual

Features

TDI/DSI
147
31
6
2
3
JTAG_EN
TCLK
TMS/BKPT
TRST/DSCLK
JTAG Module
31.1 Features
The basic features of the JTAG module are the following:
• Performs boundary-scan operations to test circuit board electrical continuity
• Bypasses instruction to reduce the shift register path to a single cell
• Sets chip output pins to safety states while executing the bypass instruction
• Samples the system pins during operation and transparently shift out the result
• Selects between JTAG TAP controller and Background Debug Module (BDM)
using a dedicated JTAG_EN pin
31-2
TAP CONTROLLER
1-BIT BYPASS REGISTER
148-BIT BOUNDARY SCAN REGISTER
32-BIT IDCODE REGISTER
7-BIT JTAG_CFM_CLKDIV REGISTER
3-BIT TEST_CTRL REGISTER
4-BIT TAP INSTRUCTION DECODER
4-BIT TAP INSTRUCTION REGISTER
Figure 31-1. JTAG Block Diagram
MCF5282 User's Manual
0
0
0
0
0
Disable DSCLK
Force BKPT = 1
DSI = 0
DSO
to Debug Module
DSI
BKPT
DSCLK
1
TDO/DSO
0
1
0
MOTOROLA