MOTOROLA
SIGNAL DESCRIPTIONS
MMC2001
4-6
REFERENCE MANUAL
4.6.3 Test Data Output (TDO)
The test data output (TDO) pin is the serial output for test instructions and data. TDO
is three-stateable and is actively driven in the shift-IR and shift-DR controller states.
TDO changes on the falling edge of TCK.
4.6.4 Test Mode Select (TMS)
The test mode select input (TMS) pin is used to sequence the test controller’s state
machine. The TMS is sampled on the rising edge of TCK. It has an internal 47-Kbyte
pull-up resistor.
4.6.5 Test Reset (TRST)
The active-low Schmitt trigger input pin TRST is used to initialize the test controller
asynchronously. The TRST pin has an internal 47-Kbyte pull-up resistor.
4.6.6 Debug Event (DE)
DE is an open drain, bidirectional, active low pin. As an input, it provides a means of
entering debug mode from an external command controller. As an output, it provides
a means of acknowledging that the CPU has entered debug mode.
This pin, when asserted as an input, causes the CPU to finish the current instruction
being executed, save the instruction pipeline information, enter debug mode, and wait
for commands to be entered from the serial debug input line. This pin is asserted as
an output for several clock cycles when the CPU enters debug mode as a result of a
debug request or as a result of meeting a breakpoint condition.
If used to enter debug mode, DE must be negated after the OnCE responds with an
acknowledge and before sending the first OnCE command. The DE pin has an inter-
nal 47-Kbyte pull-up resistor.
4.6.7 Factory Test Mode (TEST)
This input is used to select factory test mode. A description of the functionality of this
pin is detailed in the factory test document. The TEST pin has an internal 100-Kbyte
pulldown resistor.
4.7 External Interrupts/GPIO Signals
These pins provide the software with general-purpose access external to the chip.
See SECTION 13 EXTERNAL INTERRUPTS/GPIO (EDGE PORT) for more informa-
tion on these signals.
4.7.1 External Interrupts 7 – 0 (INT[7:0])
These bidirectional pins comprise the external interface to the GPIO module.
Freescale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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