Texas Instruments TMS320C80, User Manual

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Transfer Controller Differences
1-4 TMS320C80 to TMS320C82 Software Compatibility User’s Guide
1.3 Transfer Controller Differences
The differences between the transfer controllers (TCs) on the
’C80 and ’C82 are hardware differences. Generally, these differ-
ences have a negligible impact on how you write your software.
The ’C82 and ’C80 TCs differ in two main ways:
-
The ’C80 TC supports 7 XPT requests, but the ’C82 TC sup-
ports 15 XPT requests.
-
The ’C80 TC uses dedicated pins for obtaining memory con-
figuration information, but the ’C82 TC uses a configuration
cache.
1.3.1 Number of Externally Initiated Packet Transfer Requests
The number of XPT requests handled by the ’C80 and ’C82 is dif-
ferent. However, because XPT requests are driven by external
devices, the seven XPT requests shared by the ’C80 and ’C82
generally aren’t used to emulate each other in different systems
with different peripherals. For example, the likelihood is small
that the peripheral connected to XPT1 on the ’C80 software de-
velopment board (SDB) is the same as the peripheral connected
to XPT1 on a target ’C82 board. XPTs are normally handled
through software drivers that are written for each application. The
drivers for the SDB will almost always differ from the drivers used
in an actual application.
1.3.2 RAM Bank Configuration Mechanisms
The special RAM bank configuration pins on the ’C80 and the
configuration cache on the ’C82 are hardware features that have
a negligible impact on software.