19.32.3 MTB_DWT Comparator Mask Register
(MTBDWT_MASKn)
The MTBDWT_MASKn registers define the size of the ignore mask applied to the
reference address for address range matching by comparator n. Note the format of this
mask field is different than the MTB_MASTER[MASK].
Address: F000_1000h base + 24h offset + (16d × i), where i=0d to 1d
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
0
MASK
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
MTBDWT_MASKn field descriptions
Field Description
31–5
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
4–0
MASK
MASK
The value of the ignore mask, 0-31 bits, is applied to address range matching. MASK = 0 is used to
include all bits of the address in the comparison, except if MASK = 0 and the comparator is configured to
watch instruction fetch addresses, address bit [0] is ignored by the hardware since all fetches must be at
least halfword aligned. For MASK != 0 and regardless of watch type, address bits [x-1:0] are ignored in the
address comparison.
Using a mask means the comparator matches on a range of addresses, defined by the unmasked most
significant bits of the address, bits [31:x]. The maximum MASK value is 24, producing a 16 Mbyte mask.
An attempted write of a MASK value > 24 is limited by the MTBDWT hardware to 24.
If MTBDWT_COMP0 is used as a data value comparator, then MTBDWT_MASK0 should be programmed
to zero.
Chapter 19 Micro Trace Buffer (MTB)
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
Freescale Semiconductor, Inc. 319
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