Methods and apparatus for synchronizing data transfers across clock domains using heads-up indications

A system comprising:

• a first-in first-out buffer (FIFO);
• a memory configured to operate in a first clock domain and coupled to the FIFO, the first clock domain associated with a first clock signal;
• a data fabric configured to operate in a second clock domain and coupled to the FIFO, the second clock domain associated with a second clock signal, a second frequency of the second clock signal being different from a first frequency of the first clock signal;
• and
• a controller coupled to the FIFO and configured to:
• generate a first offset based on a phase relationship between the first clock signal and the second clock signal, the first clock signal, and the second clock signal;
• and
• generate a first heads-up signal based upon the first offset to a memory controller coupled to the memory.

A method implemented by a controller, comprising:

• receiving a first heads-up cycle number associated with an operation of a first memory device to a first-in first-out buffer (FIFO);
• generating a first offset based on a phase relationship between a first clock signal and a second clock signal, a second frequency of the second clock signal being different from a first frequency of the first clock signal, and based on the first clock signal and the second clock signal;
• sending a first heads-up signal based upon the first offset to the first memory device;
• and sending a first command signal based upon the first heads-up signal and the first heads-up cycle number to the FIFO.