Memory-based semaphores are described that are useful for synchronizing processes between different processing engines. In one example, operations include executing a first process at a first processing engine, the executing including updating a memory register, sending a signal from the first processing engine to a second processing engine that the memory register has been updated, the signal including a memory register address to identify the updated memory register inline data and a dataword, fetching data from the memory register by the second processing engine, comparing the fetched data to the received dataword, and conditionally executing a next command of a second process at the second processing engine based on the comparison.