
MOTOROLA
Chapter 8. Signal Descriptions
8-17
Signal Descriptions
State Meaning
Asserted—core_a_oe controls whether core_a_out[0:31] are driven
or forced to a high-impedance state.
Negated—Indicates that core_a_out[0:31]
are always driven.
Assertion/Negation—Must be set up prior to negation of the
core_hreset signal and remain stable during core operation. This is a
static configuration.
Timing Comments
8.3.3.2
Address Bus Parity
There are both address bus parity input and output signals reflecting 1 bit of odd-byte parity
for each of the 4 bytes of address when a valid address is on the bus. The G2 core also
implements an address bus parity input enable signal.
8.3.3.2.1
Address Bus Parity In (core_ap_in[0:3])
Following are the state meaning and timing comments for core_ap_in[0:3].
State Meaning
Asserted/Negated—Represents odd parity for each of 4 bytes of the
physical address for snooping operations. Detected even parity
causes the processor to take a machine check exception or enter the
checkstop state if address parity checking is enabled in the HID0
register; see Section 2.1.2.1, “Hardware Implementation Register 0
(HID0).” (See also the core_ape signal description.)
Timing Comments
Assertion/Negation—The same as core_a_in[0:31].
8.3.3.2.2
Address Bus Parity Input Enable (core_ap_ien)—Output
core_ap_ien is an input-enable indicator for its corresponding bus signals. Following are
the state meaning and timing comments for core_ap_ien when core_a_tre is negated.
State Meaning
Asserted—Indicates that the G2 core is receiving valid address
parity.
Negated—Indicates that the address parity input data is ignored.
Timing Comments
Assertion/Negation—Valid values must be presented on
core_ap_in[0:3] when core_ap_ien is asserted to the system logic.
8.3.3.2.3
Address Bus Parity Out (core_ap_out[0:3])
Following are the state meaning and timing comments for core_ap_out[0:3].
State Meaning
Asserted/Negated—Represents odd parity for each of 4 bytes of the
physical address for a transaction. Odd parity means that an odd
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