HelenOS sources

microseconds       40 kernel/generic/include/time/delay.h extern void delay(uint32_t microseconds);
microseconds      729 uspace/lib/cpp/include/__bits/chrono.hpp             constexpr chrono::microseconds operator ""us(unsigned long long usecs)
microseconds      731 uspace/lib/cpp/include/__bits/chrono.hpp                 return chrono::microseconds{static_cast<chrono::microseconds::rep>(usecs)};