MOTOROLA
Chapter 2. Signal Descriptions
2-43
2.2.7.3 JTAG Test Data Input (TDI)—Input
Following is the state meaning for the TDI input signal.
State Meaning
Asserted/Negated—The value presented on this signal on the rising
edge of TCK is clocked into the selected JTAG test instruction or
data register.
Note that this input contains an internal pull-up resistor to ensure that
an unterminated input appears as a high signal level to the test logic.
2.2.7.4 JTAG Test Mode Select (TMS)—Input
The test mode select (TMS) signal is an input on the MPC106. Following is the state
meaning for the TMS input signal.
State Meaning
Asserted/Negated—This signal is decoded by the internal JTAG TAP
controller to distinguish the primary operation of the test support
circuitry.
Note that this input contains an internal pull-up resistor to ensure that
an unterminated input appears as a high signal level to the test logic.
2.2.7.5 JTAG Test Reset (TRST)—Input
The test reset (TRST) signal is an input on the MPC106. Following is the state meaning for
the TRST input signal.
State Meaning
Asserted—This input causes asynchronous initialization of the
internal JTAG test access port controller. During power-on reset, the
system should assert TRST to reset the JTAG control logic.
Negated—Indicates normal operation.
Note that this input contains an internal pull-up resistor to ensure that
an unterminated input appears as a high signal level to the test logic.
2.2.8 Configuration Signals
The MPC106 has several signals that are sampled during power-on reset to determine the
configuration of the ROM, Flash, and dynamic memory, and the phase-locked loop clock
mode. This section describes the signals sampled during power-on reset, and how they are
configured. Weak pull-up or pull-down resistors should be used to avoid interference with
normal signal operations.
2.2.8.1 Address Map (DBG0)—Input
The address map configuration signal uses DBG0 as a configuration input. Following is the
state meaning for the DBG0 configuration signal.
State Meaning
High—Configures the MPC106 for address map A.
Low—Configures the MPC106 for address map B.
See Section 3.1, “Address Maps,” for more information.