Nonscan Chain Operation - Motorola ColdFire MCF5281 User Manual

Motorola microcontroller user's manual
Table of Contents

Advertisement

Initialization/Application Information
Using the EXTEST instruction requires a circuit-board test environment that avoids
device-destructive configurations in which MCU output drivers are enabled into actively
driven networks.
Low-power stop mode considerations:
• The TAP controller must be in the test-logic-reset state to either enter or remain in
the low-power stop mode. Leaving the test-logic-reset state negates the ability to
achieve low-power, but does not otherwise affect device functionality.
• The TCLK input is not blocked in low-power stop mode. To consume minimal
power, the TCLK input should be externally connected to V
• The TMS, TDI, and TRST pins include on-chip pull-up resistors. For minimal
power consumption in low-power stop mode, these three pins should be either
connected to V

31.6.2 Nonscan Chain Operation

Keeping the TAP controller in the test-logic-reset state ensures that the scan chain test logic
is transparent to the system logic. It is recommended that TMS, TDI, TCLK, and TRST be
pulled up. TRST could be connected to ground. However, since there is a pull-up on TRST,
some amount of current results. The internal power-on reset input initializes the TAP
controller to the test-logic-reset state on power-up without asserting TRST.
31-12
or left unconnected.
DD
MCF5282 User's Manual
.
DD
MOTOROLA

Advertisement

Table of Contents
loading

This manual is also suitable for:

Coldfire mcf5282

Table of Contents