Quality-of-service information for a multi-memory system

An apparatus, comprising:

• a non-volatile memory;
• a volatile memory configured to operate as a cache for the non-volatile memory;
• and
• an interface controller coupled with the non-volatile memory and the volatile memory, the interface controller operable to cause the apparatus to:
• receive a set of bits from a host device during a set of clock cycles and over a command bus comprising a command select pin configured for double data rate signaling;
• determine whether the set of bits represents a first command or metadata for a second command based at least in part on a state of the command select pin during at least one clock cycle of the set of clock cycles;
• determine, based at least in part on the state of the command select pin indicating that the set of bits represents metadata for the second command and on a plurality of bits included in the set of bits, quality-of-service (QoS) information for a read command received over the command bus after the set of bits;
• and
• prioritize communication of data associated with the read command to the host device based at least in part on the QoS information for the read command.

An apparatus, comprising:

• a non-volatile memory;
• a volatile memory configured to operate as a cache for the non-volatile memory;
• and
• an interface controller coupled with the non-volatile memory and the volatile memory, the interface controller operable to cause the apparatus to:
• receive a set of bits from a host device during a set of clock cycles and over a command bus comprising a command select pin configured for double data rate signaling;
• determine whether the set of bits represents a first command or metadata for a second command based at least in part on a state of the command select pin during at least one clock cycle of the set of clock cycles;
• determine, based at least in part on the state of the command select pin indicating that the set of bits represents metadata for the second command and on a plurality of bits included in the set of bits, quality-of-service (QoS) information for a write command received over the command bus after the set of bits;
• and
• prioritize communication of the write command to the non-volatile memory or the volatile memory based at least in part on the QoS information for the write command.