About adaptive clocking

Adaptive clocking enables your debug hardware unit to dynamically adjust the JTAG clock (TCK) following changes to the processor clock (CLK). This is useful when debugging system with low power modes and changing clocks in general.

Adaptive clocking is intended only for targets that are based on a synthesizable ARM® processor implementing RTCK. When a fixed JTAG clock is used, the JTAG clock must be running at most 1/6 of the processor clock. Using a fixed JTAG clock does not support changes in the processor clock speed, which can corrupt the JTAG connection.

If you use adaptive clocking, the maximum clock frequency is lower than with non-adaptive clocking, because of transmission delays, gate delays, and synchronization requirements.

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ARM® DSTREAM™ System and Interface Design Reference:

ARM® RVI™ and RVT™ System and Interface Design Reference:

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