Motorola MCF5281 사용자 설명서
31-2
MCF5282 User’s Manual
MOTOROLA
Features
Figure 31-1. JTAG Block Diagram
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)
• 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
4-BIT TAP INSTRUCTION REGISTER
3
0
1-BIT BYPASS REGISTER
148-BIT BOUNDARY SCAN REGISTER
32-BIT IDCODE REGISTER
TRST/DSCLK
TCLK
TMS/BKPT
0
31
0
147
TAP CONTROLLER
TDI/DSI
1
0
TDO/DSO
JTAG Module
to Debug Module
7-BIT JTAG_CFM_CLKDIV REGISTER
0
6
3-BIT TEST_CTRL REGISTER
0
2
4-BIT TAP INSTRUCTION DECODER
1
0
Disable DSCLK
Force BKPT = 1
Force BKPT = 1
DSI = 0
JTAG_EN
DSO
DSI
BKPT
DSCLK
BKPT
DSCLK