
MOTOROLA
Chapter 8. Signal Descriptions
8-35
Signal Descriptions
8.3.7.2.2
Data Bus Parity Input Enable (core_dp_ien)—Output
core_dp_ien is an input-enable indicator to its corresponding bus signals. Following are the
state meaning and timing comments for core_dp_ien when core_dp_tre is negated.
State Meaning
Asserted—Indicates that the G2 core is excepting valid data bus
parity.
Negated—Indicates that the data bus parity input is ignored.
Timing Comments
Assertion/Negation—Valid data must be presented to
core_dp_in[0:7] when core_dp_ien is asserted to the system logic.
These signals allow integrators to support either a bidirectional or
unidirectional data bus parity interface.
8.3.7.2.3
Data Bus Parity Out (core_dp_out[0:7])
Following are the state meaning and timing comments for core_dp_out[0:7].
State Meaning
Asserted/Negated—Represents odd parity for each of 8 bytes of data
for write transactions. Odd parity means that an odd number of bits,
including the parity bit, are driven high.
Timing Comments
Assertion/Negation—The same as core_dl_out[0:31].
High Impedance—The same as core_dl_out[0:31].
8.3.7.3
Data Parity Error (core_dpe)—Output
The core_dpe signal is an output signal (output-only) on the G2 core. The core also
implements data parity error output enable and data parity error high-impedance enable
signals. core_dpe acts as follows:
If core_dpe_tre is asserted, the output is in one of the following three states—high
impedance, driven high, or driven low.
If core_dpe_tre is negated, the output is either driven to the high or low state. In this
case, a valid value on core_dpe exists when core_dpe_oe is asserted.
Following are the state meaning and timing comments for the core_dpe output.
State Meaning
Asserted—Indicates that incorrect data bus parity was detected
during a read transaction when HID0[EBD] is enabled. Internally,
the core can take a machine check interrupt or enter a checkstop
state.
Negated—Indicates correct data bus parity on the data bus.
Timing Comments
Assertion—Occurs on the second bus clock cycle after core_ta is
asserted to the core, unless core_ta is canceled by an assertion of
core_drtry or core_artry (in certain cases).
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