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MPC106 PCIB/MC User's Manual
MOTOROLA
2.2.6.6 Suspend (SUSPEND)—Input
The suspend (SUSPEND) signal is an input on the MPC106. Following are the state
meaning and timing comments for the SUSPEND input signal.
State Meaning
Asserted—Activates the suspend power-saving mode.
Negated—Deactivates the suspend power-saving mode.
Timing Comments
Assertion—The SUSPEND signal can be asserted at any time,
asynchronous to the 60x bus clock. The MPC106 synchronizes
SUSPEND internally.
Negation—The SUSPEND signal can be negated at any time,
asynchronous to the 60x bus clock, as long as it meets the timing
requirements for turning the PLL and external clock on and off when
entering and exiting suspend mode.
2.2.6.7 System Clock (SYSCLK)—Input
The system clock (SYSCLK) signal is an input on the MPC106. The SYSCLK signal sets
the frequency of operation for the PCI bus, and provides a reference clock for the phase-
locked loops in the MPC106. SYSCLK is used to synchronize bus operations. See
Section 2.3, “Clocking,” for more information.
2.2.7 IEEE 1149.1 Interface Signals
To facilitate system testing, the MPC106 provides a JTAG test access port (TAP) that
complies with the IEEE 1149.1 boundary-scan specification. This section describes the
JTAG test access port signals.
2.2.7.1 JTAG Test Clock (TCK)—Input
The JTAG test clock (TCK) signal is an input on the MPC106. Following is the state
meaning for the TCK input signal.
State Meaning
Asserted/Negated—This input should be driven by a free-running
clock signal with a 50% duty cycle. Input signals to the test access
port are clocked in on the rising edge of TCK. Changes to the test
access port output signals occur on the falling edge of TCK. The test
logic allows TCK to be stopped.
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.
2.2.7.2 JTAG Test Data Output (TDO)—Output
Following is the state meaning for the TDO output signal.
State Meaning
Asserted/Negated—The contents of the selected internal instruction
or data register are shifted out onto this signal on the falling edge of
TCK. The TDO signal will remain in a high-impedance state except
when scanning of data is in progress.