
MOTOROLA
Chapter 8. Signal Descriptions
8-19
Signal Descriptions
State Meaning
Asserted—Indicates that the G2 core is driving a valid core_ape.
Negated—Indicates one of the following two conditions:
If core_ape_tre is negated, negated core_ape_oe indicates that the
core is not driving a valid core_ape value.
If core_ape_tre is asserted, negated core_ape_oe indicates that
core_ape is in the high-impedance state.
Assertion—core_ape_oe is asserted on the second bus clock after the
assertion of core_ts_in.
Negation—Occurs on the third bus clock cycle after core_ts_in is
asserted.
Note that negation of core_ape_oe may force core_ape to the
high-impedance state, if core_ape_tre is asserted.
Timing Comments
8.3.3.3.2
Address Parity Error High-Impedance Enable (core_ape_tre)—
Input
Following are the state meaning and timing comments for core_ape_tre. core_ape_tre is a
high-impedance enable signal on the G2 core and can be used to create a three-statable
version of core_ape externally. The resulting core_ape output signal functions similar to a
bidirectional 60x bus signal when core_ape_tre is asserted.
State Meaning
Asserted—core_ape_oe controls whether core_ape is driven or
forced to a high-impedance state.
Negated—Indicates that core_ape is always driven.
Timing Comments
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.
8.3.4
Address Transfer Attribute Signals
The transfer attribute signals are a set of signals that further characterize the transfer—such
as the size of the transfer, whether it is a read or write operation, and whether it is a burst
or single-beat transfer. For a detailed description of how these signals interact, see
Section 9.3.2, “Address Transfer.”
8.3.4.1
Transfer Type
The transfer type signals consist of five inputs and five outputs on the G2 core. For a
complete description of the transfer type signals and for transfer type encodings, see
Table 8-6.
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.