Returns the number of elapsed target ticks since execution started. Use SYS_TICKFREQ to determine the tick frequency.


On entry, R1 points to a two-word data block to be used for returning the number of elapsed ticks:

word 1

the least significant word and is at the low address

word 2

the most significant word and is at the high address.


On exit:

  • On success, R1 points to a doubleword that contains the number of elapsed ticks. On failure, R1 contains -1.

  • On success, R0 contains 0. On failure, R0 contains -1.


Some debuggers might not support this SVC when connected though RVI or DSTREAM, and they always return -1 in R0.

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