8.7. TPIU trace port sizes
The TPIU is configured for the largest port size allowable,
32 bits of TRACEDATA, TRACECLK,
and TRACECTL.
TRACECLK is
always exported to enable synchronization back with the data and
so is not optional.
TRACECTL is required
unless a new TPA is used that is aware of the formatter protocol
which can remove extra packets used to expand data sequences. For Normal
and Bypass modes, TRACECTL must
be present.
TRACEDATA can
be defined as any size up to 32 bits. For backwards compatibility
and usage with ETMv3 trace capture devices, a minimum port width
of 2 bits is permitted, that is, TRACEDATA[1:0].
Table 8.19 shows
some typical Trace Out Port sizes.
Table 8.19. Example Trace Out Port sizes
| TRACECLK present | TRACECTL present | TRACEDATA width | Total pin count | Comment |
|---|
| Yes | Yes | 32 bits [31:0] | 34 | Largest implementation |
| Yes | No | 9 bits [8:0] | 10 | Extra data pin available in comparison to the typical
ETM implementation. |
| Yes | Yes | 8 bits [7:0] | 10 | Typical ETM-compatible TPA implementation. |
| Yes | Yes | 2 bits [1:0] | 4 | Smallest implementation with typical TPAs. |
| Yes | No | 1 bit [0] | 2 | Smallest implementation with a protocol-aware
TPA |
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