The AHB-AP has two clock domains:
Drives the DAP bus interface and access control for register read and writes. DAPCLK must be driven by a constant clock. When started, it must not be stopped or altered while the DAP is in use.
DAPCLK can be connected to HCLK or can be asynchronous to HCLK, if there are other APs in the SoC that cannot operate at full HCLK.
AHB clock domain driving AHB interface.
Initializes the state of all registers in the AHB-AP.