User guide

Embedded Trace Macrocell
ARM DDI 0337I Copyright © 2005-2008, 2010 ARM Limited. All rights reserved. 10-13
ID072410 Non-Confidential
[6:4] Port size [2:0] The ETM-M3 has no influence over the external pins used for trace. These bits are implemented
but not used.
On an ETM reset these bits reset to
0b001
.
[3:1] - Reserved
[0] ETM power down This bit can be used by an implementation to control if the ETM is in a low power state. This bit
must be cleared by the trace software tools at the beginning of a debug session.
When this bit is set to 1, writes to some registers and fields might be ignored. You can always write
to the following registers and fields:
ETMCR bit [0]
•ETMLAR
ETMCLAIMSET register
ETMCLAIMCLR register.
When the ETMCR is written with this bit set to 1, bits other than bit [0] might be ignored.
On an ETM reset this bit is set to 1.
Table 10-7 ETMCR bit assignments (continued)
Bits Name Function