mcf5407 Freescale Semiconductor, Inc, mcf5407 Datasheet - Page 475

• Manufacturer Part Number: mcf5407
• Description: Mcf5407 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

19.7 Obtaining the IEEE Standard 1149.1
The IEEE Standard 1149.1 JTAG specification is a copyrighted document and must be
• Nonuse of JTAG test logic by either nontermination (disconnection) or intentionally
• Disabling JTAG test logic by holding MTMOD0 low during reset (debug mode).
fixing TAP logic values. The following issues must be addressed if IEEE Standard
1149.1 logic is not to be used when the MCF5407 is assembled onto a board.
— IEEE Standard 1149.1 test logic must remain transparent and benign to the
— TCK has no internal pull-up as is required on TMS, TDI, and TRST; therefore,
This allows the IEEE Standard 1149.1 test controller to enter test-logic-reset state
when TRST is internally asserted to the controller. TAP pins function as debug mode
pins. In JTAG mode, inputs TDI/DSI, TMS/BKPT, and TRST/DSCLK have internal
pull-ups enabled. Figure 19-5 shows pin values recommended for disabling JTAG in
debug mode.
system logic during functional operation. To ensure that the part enters the
test-logic-reset state requires either connecting TRST to logic 0 or connecting
TCK to a source that supplies five rising edges and a falling edge after the fifth
rising edge. The recommended solution is to connect TRST to logic 0.
it must be terminated to preclude mid-level input values. Figure 19-4 shows pin
values recommended for disabling JTAG with the MCF5407 in JTAG mode.
Figure 19-5. Disabling JTAG in Debug Mode
Figure 19-4. Disabling JTAG in JTAG Mode
Chapter 19. IEEE 1149.1 Test Access Port (JTAG)
Debug Interface
Note: MTMOD0 high allows JTAG mode.
Note: MTMOD0 low prohibits JTAG.
VDD
•
•
•
TMS/BKPT
TDI/DSI
TRST/DSCLK
TCK
TDI/DSI
TMS/BKPT
TRST/DSCLK
TCK
Obtaining the IEEE Standard 1149.1
19-11