Table 12-19 Control Of Pushed Operation Comparisons By Masklane - ARM Cortex-M3 Technical Reference Manual

Debug Port
Bits Access Function
[1] b STICKYORUN
RO
[0] R/W ORUNDETECT
a. Implemented on SW-DP only. On a JTAG-DP this bit is Reserved, RAZ/SBZP.
b. RO on SW-DP. On a JTAG-DP, this bit can be read normally, and writing b1 to this bit clears the bit to b0.
12-56
Table 12-18 Control/Status Register bit assignments (continued)
Description
If overrun detection is enabled (see bit [0] of this register),
this bit is set to 1 when an overrun occurs. To clear this bit:
On a JTAG-DP Write b1 to this bit of this register.
On a SW-DP Write b1 to the ORUNERRCLR field of
After a reset this bit is Low (0).
This bit is set to b1 to enable overrun detection.
After a reset this bit is Low (0).
MASKLANE and the bit masking of the pushed compare and pushed verify
operations
The MASKLANE field, bits [11:8] of the CTRL/STAT Register, is only relevant if the
Transfer Mode is set to pushed verify or pushed compare operation, see Transfer mode
(TRNMODE), bits [3:2] on page 12-57.
In the pushed operations, the word supplied in an AP write transaction is compared with
the current value of the target AP address. The MASKLANE field lets you specify that
the comparison is made using only certain bytes of the values. Each bit of the
MASKLANE field corresponds to one byte of the AP values. Therefore, each bit is said
to control one byte lane of the compare operation.
Table 12-19 shows how the bits of MASKLANE control the comparison masking.

Table 12-19 Control of pushed operation comparisons by MASKLANE

a Meaning
MASKLANE
b1XXX Include byte lane 3 in comparisons.
bX1XX Include byte lane 2 in comparisons.
bXX1X Include byte lane 1 in comparisons.
bXXX1 Include byte lane 0 in comparisons.
a. Bits [11:8] of the CTRL/STAT Register.
b. Bytes of the mask shown as -- are determined by the other bits of MASKLANE.
Copyright © 2005, 2006 ARM Limited. All rights reserved.
the Abort Register, see The Abort Register,
ABORT on page 12-49.
Mask used for comparisons
0xFF------
0x--FF----
0x----FF--
0x------FF
Required?
Yes
Yes
b
ARM DDI 0337B