Jtag Signals; Test Clock (Tck); Test Mode Select (Tms); Test Data Input (Tdi) - Motorola DSP56305 User Manual

11.2

JTAG SIGNALS

As described in the IEEE 1149.1 document, the JTAG port requires a minimum of four
signals to support TDI, TDO, TCK, and TMS signals. The DSP56300 family also provides
the optional TRST signal. On the DSP56305, the Debug Event (DE) signal is provided for
use by the OnCE module; it is described in
signal functions are described in the following paragraphs.
11.2.1

Test Clock (TCK)

The Test Clock Input (TCK) Signal is used to synchronize the test logic.
11.2.2

Test Mode Select (TMS)

The Test Mode Select Input (TMS) Signal is used to sequence the test controller's state
machine. The TMS is sampled on the rising edge of TCK and it has an internal pullup
resistor.
11.2.3

Test Data Input (TDI)

Serial test instruction and data are received through the Test Data Input (TDI) Signal.
TDI is sampled on the rising edge of TCK and it has an internal pullup resistor.
11.2.4

Test Data Output (TDO)

The Test Data Output (TDO) Signal is the serial output for test instructions and data.
TDO is tri-stateable and is actively driven in the Shift-IR and Shift-DR controller states.
TDO changes on the falling edge of TCK.
11.2.5

Test Reset (TRST)

The Test Reset Input (TRST) Signal is used to asynchronously initialize the test
controller. The TRST signal has an internal pullup resistor.
MOTOROLA
Section 10, On-Chip Emulation Module
DSP56305 User's Manual
JTAG Port
JTAG Signals
. The
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