SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
The A53SS has two timebase input interfaces:
Both of them are fed by the Global Timebase Counter (GTC), which provides a 64-bit graycode value. The A53SS includes two graycode decoders (for global time and debug time, respectively), which take the asynchronous graycoded times, synchronize them to the appropriate clock, and convert them to binary time, as required by Arm.
Both graycode decoders are 64-bit but the one dedicated to debug time has a 48-bit input (the upper 16 bits are tied to 0).
For more details on the GTC, see Global Timebase Counter (GTC).