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Chapter 6: Solving Problems
If emulation memory addressing appears incorrect
If emulation memory addressing appears
incorrect
The 68360 emulator has limited addressing when the upper address bits, A(31-28),
are programmed as WE(3-0). The following paragraphs explain the addressing
limitations.
Bits A(31-28) are not available from the 68360 microprocessor when they are
programmed as WE(3-0). The emulator uses information in the programming of
the chip selects to recreate A(31-28). Recreated bits A(31-28) are supplied to the
analyzer so symbolic debugging can be done in the trace list. Unfortunately,
A(31-28) cannot be recreated fast enough to be used by the emulation memory
mapper. In this mode, A(31-28) are set to 0 and mapping is limited to the lower 28
bits of address information.
The configuration of A(31-28)/WE(3-0) can be seen using the terminal interface
command:
M>info upperaddr
The way the hardware interprets the four upper-address lines is shown in the
following diagram:
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