Features

TAP CONTROLLER

TDI/DSI

1-BIT BYPASS REGISTER

 

 

 

 

 

 

 

 

147

0

 

 

 

148-BIT BOUNDARY SCAN REGISTER

 

 

 

31

0

 

 

 

32-BIT IDCODE REGISTER

 

 

1

 

6

0

 

 

 

TDO/DSO

 

7-BIT JTAG_CFM_CLKDIV REGISTER

 

0

 

2

0

 

 

 

3-BIT TEST_CTRL REGISTER

 

 

 

 

4-BIT TAP INSTRUCTION DECODER

 

 

 

3

0

 

 

 

4-BIT TAP INSTRUCTION REGISTER

 

 

JTAG_EN

 

 

 

 

TCLK

 

Disable DSCLK

 

TMS/BKPT

 

1

 

Force BKPT = 1

TRST/DSCLK

 

DSI

= 0

0

 

 

 

 

 

JTAG Module

 

 

 

to Debug Module

DSO

DSI

BKPT DSCLK

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) using a dedicated JTAG_EN pin

31-2

MCF5282 User’s Manual

MOTOROLA

Page 732
Image 732
Motorola MCF5282, MCF5281 user manual Jtag Block Diagram