trace/coresight/coresight-ect.rst

1 .. SPDX-License-Identifier: GPL-2.0
4 CoreSight Embedded Cross Trigger (CTI & CTM).
11 --------------------
13 The CoreSight Cross Trigger Interface (CTI) is a hardware device that takes
21  0 C   0----------->:     :             +======>(other CTI channel IO)
22  0  P  0<-----------:     :             v
24  0000000            : CTI :<=========>*CTM*<====>: CTI :---+
25  #######  in_trigs  :     : (id 0-3)  *****      :::::::   v
26  # ETM #----------->:     :                         ^   #######
27  #     #<-----------:     :                         +---# ETR #
41 CoreSight devices on the trace data path. When these devices are enabled the
50 The hardware trigger signals can also be connected to non-CoreSight devices
60 ---------------------------
62 The CTI devices appear on the existing CoreSight bus alongside the other
63 CoreSight devices::
65     >$ ls /sys/bus/coresight/devices
71 can be associated with other CoreSight devices, or other system hardware
74   >$ ls /sys/bus/coresight/devices/etm0/cti_cpu0
78 *Key file items are:-*
82    * ``ctmid`` : associated CTM - only relevant if system has multiple CTI+CTM
84    * ``nr_trigger_cons`` : total connections - triggers<N> directories.
87 *Sub-directories:-*
89    * ``channels``: Contains the channel API - CTI main programming interface.
91    * ``mgmt``: the standard CoreSight management registers.
92    * ``connections``: Links to connected *CoreSight* devices. The number of
101 CoreSight and non-CoreSight connections.
119     0-2
123     0-1
135 'regs' sub-directory elements directly.
166    * ``chan_set``: Set the channel - the set state will be propagated around
169    * ``chan_pulse``: Set the channel for a single CoreSight clock cycle.
208    0-1,3