D.3.1. Delayed clock probe

This probe is to be used with target boards that do not meet the required set-up and hold times between transitions on the data and clock lines, as specified in Signal requirements.

This probe is similar in overall shape and size to the one shown in Figure D.2, but its reverse side comprises a set of switches that you are to manipulate according to the function that you require from the target board, namely to:

Table D.1 shows the switch configurations that you must set to obtain your required function. The ASYNC switch, however, is controlled by code, and not by physical manipulation of switch positions.

Table D.1. Probe switch settings

SwitchFunctionSwitch 1 positionSwitch 2 position
NormalRVT modeOffOn
InvertedInverts TRACECLKOnOn
Delay 1Delays TRACECLK by 2.25nsOnOff
Delay 2Delays TRACECLK by 2.75nsOffOff
ASYNCAsynchronous samplingN/AN/A

The layout and location of these switches are shown in Figure D.3.

Figure D.3. Delayed clock probe showing location of switches


Figure D.3 shows Switch 1 in the Off position, and Switch 2 in the On position.

Five mode LEDs, located to the left of the switches, are used to indicate when the unit is powered-up, and which mode is currently active. Only one mode LED lights up at any one time. Each of these LEDs corresponds to the function denoted by the switch configuration that you have set.

The five mode LEDs are identified on the PCB as follows:

Note

The ASYNC mode facility is included here for descriptive purposes. Its intended use is for future enhancement of the system.

If you require a delayed clock probe, contact ARM Limited for more information.

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