CoreSight Program Flow Trace Architecture Specification: 3.16.13. Address Comparator Access Type Registers, ETMACTRn

3.16.13. Address Comparator Access Type Registers, ETMACTRn

The ETMACTR characteristics are:

Purpose

Specifies the type of access, for example instruction or data, and other comparator configuration information for an address comparison.

Usage constraints

Each ETMACTR is used with the corresponding ETMACVR. See Address Comparator Value Registers, ETMACVRn.

Configurations

The number of ETMACTR pairs:

is implementation defined
is specified by ETMCCR bits [3:0].
can be zero.

See Configuration Code Register, ETMCCR.

Unimplemented ETMACTRs are RAZ/WI.

Attributes

See the register summary in Table 3.16.

Figure 3.22 shows the ETMACTR bit assignments from PFTv1.1.

Figure 3.22. ETMACTR bit assignments from PFTv1.1

Figure 3.23 shows the ETMACTR bit assignments for PFTv1.0.

Figure 3.23. ETMACTR bit assignments, PFTv1.0

Table 3.27 shows the ETMACTR bit assignments.

Table 3.27. ETMACTR bit assignments

Bits	Description
[31:16]	Reserved, SBZP.
[15]	For PFTv1.0 this bit is Reserved, SBZP.
[15]	From PFTv1.1 this bit sets the Virtual Machine ID (VMID) comparison enable, if the processor implements the Virtualization Extensions.^[a] A value of 1 means that the address comparator matches only if the current VMID matches the value stored in the ETMVMIDCVR. See VMID Comparator Value Register, ETMVMIDCVR. This bit is reserved, RAZ if the processor does not implement the Virtualization extensions.
[14]	For PFTv1.0 this bit is Reserved, SBZP.
[14]	From PFTv1.1 this bit sets the Hyp mode comparison enable, if the processor implements the Virtualization Extensions.^[a] A value of 1 means that the address comparator also matches if the processor is operating in Hyp mode. See Virtualization. This bit is reserved, RAZ if the processor does not implement the Virtualization extensions.
[13:10]	For PFTv1.0: bits [13:12] are Reserved, SBZP bits [11:10] are described elsewhere in this table.
[13:10]	From PFTv1.1 these bits set state and mode comparison control. The assignment of these bits is: Bit [13, 11] Non-secure state comparison control. Bit [12, 10] Secure state comparison control. For each pair of bits, the encoding is: b00 Match in all modes in this state. b01 Do not match in any modes in this state. b10 Match in all modes except User mode in this state. b11 Match only in User mode in this state. If the processor does not implement the Security Extensions, bits [13, 11] are reserved, RAZ/WI. See Filtering by state and mode, from PFTv1.1
[11:10]	Security level control. The permitted values of this field are: b00 Security level ignored. b01 Match only if in Non-secure state. b10 Match only if in Secure state. The value of b11 is reserved and must not be used. This field is available only if the connected processor implements the Security Extensions. If the Security Extensions are not implemented then these bits are RAZ/WI. This description is valid only for PFTv1.0. For PFTv1.1 and later, see the description of bits [13:10] in this table.
[9:8]	Context ID comparator control. The permitted values of this field are: b00 Ignore Context ID comparator. b01 Address comparator matches only if Context ID comparator value 1 matches. b10 Address comparator matches only if Context ID comparator value 2 matches. b11 Address comparator matches only if Context ID comparator value 3 matches.
[7:3]	Reserved, SBZP.
[2:0]	Access type. This field is read-only, and ignores writes. It returns the value: b001 Instruction execute. Note Other ARM trace architectures permit address matching conditional on the type of access and support different values for this field.
^[a]If bit [26] of the ETMCCER is zero, it indicates that Virtualization support is not implemented. See Virtualization for more information.

Each of ETMACTR has the same bit assignments.

Filtering by state and mode, from PFTv1.1

From PFTv1.1 a PTM can base address matching on:

any mode or state
any mode in Secure state
any mode in Non-secure state.

ETMACTR[13:10], the State and mode control field, defines the conditions for an address match, as:

Table 3.28 shows for an implementation that includes the Security Extensions
Table 3.29 shows for an implementation that does not include the Security Extensions.

In addition, when the Virtualization Extensions are implemented, ETMACTR[15:14] control matching in Hyp mode and on VMID, see Table 3.29. For these bits:

When bit [15] VMID comparison enable is set, no match is recognized unless the current VMID matches the value stored in the ETMVMIDCVR.
When bit [14] Hyp mode comparison enable is set, Hyp mode is considered as an additional criterion with the modes in Table 3.28. That is, operation in Hyp mode always produces a match.

Table 3.28. Address comparator filtering by state and mode, PFTv1.1 with Security Extensions

Bits [13:10]	Secure state		Non-secure state
Bits [13:10]	Kernel modes	User mode	Kernel modes	User mode
b0000	Yes	Yes	Yes	Yes
b0001	-	-	Yes	Yes
b0010	Yes	Yes	-	-
b0011	-	-	-	-
b0100	Yes	-	Yes	Yes
b0101	-	Yes	Yes	Yes
b0110	Yes	-	-	-
b0111	-	Yes	-	-
b1000	Yes	Yes	Yes	-
b1001	-	-	Yes	-
b1010	Yes	Yes	-	Yes
b1011	-	-	-	Yes
b1100	Yes	-	Yes	-
b1101	-	Yes	Yes	-
b1110	Yes	-	-	Yes
b1111	-	Yes	-	Yes

Table 3.29. Address comparator filtering by state and mode, PFTv1.1, no Security Extensions

Bits [13:10] ^[a]	Privileged modes	User mode	Matches in
b0000	Yes	Yes	All modes
b0001	-	-	Never matches
b0100	Yes	-	Privileged modes only
b0101	-	Yes	User mode only
^[a]Bits [13,11] are RAZ/WI if the processor does not implement the Security Extensions.

Access types for address range comparators

If you are using two address comparators as an address range comparator, the access type must be identical for each, otherwise the behavior of the comparator is unpredictable. The only exceptions to this are:

Bits [6:5] must be set only for the first comparator in the pair. These bits control data value comparisons.
The special case where the range includes the address 0xFFFFFFFF. See Selecting a range to include address 0xFFFFFFFF.

Note

This information is also given in Address comparators.

Selecting a range to include address 0xFFFFFFFF

Ranges are defined to be exclusive of the upper address, so if you specify an upper address of 0xFFFFFFFF, only addresses up to and including 0xFFFFFFFE match. To specify a data address to include 0xFFFFFFFF, configure the upper address comparator as follows:

Set the comparator value in the ETMACVR to 0xFFFFFFFF
set the size mask, bits [4:3] of the ETMACTR, to b11.

This is the only case where the size mask can be different between the two address comparators of an address range comparator.

For more information, see Address comparators.

Copyright © 1999-2002, 2004-2008, 2011 ARM. All rights reserved.	ARM IHI 0035B
Non-Confidential	ID060811
PDF version