mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 665

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

Chapter 31
IEEE 1149.1 Test Access Port (JTAG)
The Joint Test Action Group, or JTAG, is a dedicated user-accessible test logic, that complies with the
IEEE 1149.1 standard for boundary-scan testability, to help with system diagnostic and manufacturing
testing.
This architecture provides access to all data and chip control pins from the board-edge connector through
the standard four-pin test access port (TAP) and the JTAG reset pin, TRST.
Figure 31-1
Freescale Semiconductor
TRST/DSCLK
TMS/BKPT
JTAG_EN
TDI/DSI
TCLK
shows the block diagram of the JTAG module.
JTAG Module
147
31
6
2
3
148-BIT BOUNDARY SCAN REGISTER
7-BIT JTAG_CFM_CLKDIV REGISTER
4-BIT TAP INSTRUCTION DECODER
4-BIT TAP INSTRUCTION REGISTER
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
1-BIT BYPASS REGISTER
3-BIT TEST_CTRL REGISTER
32-BIT IDCODE REGISTER
TAP CONTROLLER
Figure 31-1. JTAG Block Diagram
to Debug Module
Disable DSCLK
Force BKPT = 1
0
0
0
0
0
DSI
= 0
DSO
DSI
BKPT
DSCLK
0
1
1
0
TDO/DSO
31-1