AMBA™ AHB Trace Macrocell (HTM) Technical Reference Manual 3.3.21. HTM AMBA Control Select Registers, HTMHCTRLSEL0-7

3.3.21. HTM AMBA Control Select Registers, HTMHCTRLSEL0-7

The HTMHCTRLSEL Registers select the values for AMBA control comparators.

Figure 3.28 shows the bit assignments.

Figure 3.28. HTMHCTRLSEL Register bit assignments

Table 3.29 shows the bit assignments.

Table 3.29. HTMHCTRLSEL Register bit assignments

Bits	Name	Function
[31:5]	Reserved	Reserved. Read as zero, do not modify.
[4]	STICKY	Output mode. 0 = Output only high when HREADY=1 1 = Output stays unchanged until next active traced transfer is detected (HREADY=1, HTRANS[1] =1 and trace is allowed by security settings).
[3:0]	SEL	Select AMBA control signal for compare.

Bits

Name

Function

[31:5]

Reserved

Reserved. Read as zero, do not modify.

[4]

STICKY

Output mode.

0 = Output only high when HREADY=1

1 = Output stays unchanged until next active traced transfer is detected (HREADY=1, HTRANS[1] =1 and trace is allowed by security settings).

[3:0]

SEL

Select AMBA control signal for compare.

Table 3.30 shows the SEL key to Figure 3.29.

Table 3.30. SEL values key

Abbreviation	Meaning	Remarks
D2-D0	Data	Lowest three bits of the extracted data on the data bus
HB	HBSTRB	-
HBR	HBurst	-
HD	HDOMAIN	-
HM	HMASTER	-
HML	HMASTLOCK	-
HP	HPROT	-
HS	HSIZE	-
HT	HTRANS	-
HUN	HUNALIGN	-
HW	HWRITE	-
Res	Response	See Table 3.12 for encoding
SC	SELCODE	See Table 3.13 for encoding
WR[1:0]	Wait range	Wait state range: Bit 0 is set to 1 if the number of wait state is over 15 Bit 1 is set to 1 if the number of wait state is over 31

Figure 3.29 shows the compared signals for the values of SEL.

Figure 3.29. SEL values and AMBA control comparators

The various SEL combinations are used as follows:

Combinations 0x0-0xD

The AMBA control comparators can be used for event generations and can work with address comparators (see HTM Address Type Registers, HTMADDRTYPE0-15). Eleven possible combinations are provided to enable comparison of multiple signals at the same time.

Combinations 0xE and 0xF

The AMBA control comparators can be used for trigger generation when the HTMHCTRLSEL register is set to 0xE or 0xF. When these combinations are used, the output result from the AMBA control comparator is not timing-accurate and therefore must not be used for trace filtering, otherwise the traced filtering behavior will be unpredictable. In addition, do not enable the use of these control comparison in address comparator setting. However, these combinations can be used for generating triggers in trace or cross trigger to other trace devices such as ETM:

Combination 0xE is useful to detect when a certain slave is selected, or when an error response is generated, or to detect when wait states exceed a certain range of clock cycles.
Combination 0xF is useful for debugging semaphore operation.

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