AMBA™ AHB Trace Macrocell (HTM) Technical Reference Manual 2.5.3. Resource identification

To identify a resource requires seven bits:

Table 2.3 describes the resource encoding.

Table 2.3. Resource encodings

Bit	Description
[6:4]	Resource type
[3:0]	Resource index

Table 2.4 defines the available resource types and lists the bit encodings used to identify them.

Table 2.4. HTM resource identification encoding

Resource type	Index range	Description
b000	0-15	Single address comparator 0-15
b001	0-7	Address range comparator 0-7 Represents the range between two single address comparators
b010	0-7	AMBA Control comparator 0-7
b011	-	Reserved
b100	0-3	Counter 0-3 at zero
b101	0-2 3-14 15	Sequencer in states1-3 Reserved Trace enable start/stop resource
b110	0-3 4-14 15	External inputs 1-4 Reserved Hard-wired input (always true)
b111	-	Reserved

When a particular resource is active, its output is a logical 1.

To permanently enable an event, you can specify the hard-wired input to A, using either function "A OR B" or "A OR NOT B" to produce the always 1 result.
To permanently disable an event, you can specify the hard-wired input to A, using either function "NOT A AND B" or "NOT A AND NOT B" to produce the always 0 result.

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