10.2.3. APB and ATB reset

PRESETn is used to reset the debug hardware within the processor in addition to the ETM CLK domain. ATRESETn is used to reset the ATB interface and Cross Trigger Interface (CTI). To safely reset the debug hardware, ATB, and CTI domains, PRESETn and ATRESETn must be asserted for a minimum of eight clock cycles of the slowest of CLK, PCLK, or ATCLK. Figure 10.8 shows the assertion of PRESETn and ATRESETn.

Figure 10.8. PRESETn and ATRESETn assertion


PRESETn and ATRESETn must always be asserted simultaneously.

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