Methods, devices and systems for high speed transactions with nonvolatile memory on a double data rate memory bus

A method of operating a memory system, comprising:

• receiving from a host, a plurality of consecutive commands on a unidirectional command-address (CA) bus input of a discrete nonvolatile memory (NVM) device, the commands being synchronous with a timing clock;
• for each received command, determining if the command is an express read (NVR) command;
• if the command is determined to be an NVR command, determining if a next consecutive command is an NVR command, wherein two consecutive NVR commands form an NVR command sequence;
• in response to the NVR command sequence, accessing read data stored in NVM cells of the discrete NVM device;
• and
• driving the read data on parallel data input/outputs (I/Os) of the NVM device in a burst of data values, the data values of the burst being output in synchronism with rising and falling edges of the timing clock, wherein the CA bus input includes a plurality of parallel CA signal inputs.

A method of operating a memory system, comprising:

• issuing, by a host, sequences of two consecutive express memory read (NVR) commands, wherein each NVR command includes distinguishing bit values from other commands;
• determining, by a command decoder of a memory device, if a received command through a unidirectional CA bus from the host is an NVR command, wherein two consecutive received NVR commands form an NVR command sequence;
• receiving via the CA bus and being determined by the command decoder, first and second NVR command sequences, wherein there is no intervening command data between the first and second NVR command sequences;
• accessing, in response to the first and second NVR command sequences, at least one NVM array of the memory device, for data stored therein;
• and
• outputting first and second read data to the host via a bidirectional data bus, corresponding respectively to the first and second NVR command sequences, wherein there is no intervening read data between the first and second read data.