Early read start time for random access ssds

Abstract

Instead of waiting for a write command to complete, a coherency table in a solid state drive (SSD) will expedite the read command start time. The coherency table allows a response to the write command will be sent to the host as soon as a write command is received. The coherency table will continue to process the write command through to the encryption/decryption (XTS) module and then over to the DRAM as normal. Once the read command reaches the coherency table, the command will be assessed for any issues. If there is an issue detected, then the coherency table will delay the read command until the previous write command reaches the DRAM (after going through the XTS module). Once the data from the write command reaches the DRAM the coherency table is cleared, and the read command is no longer delayed. The data can now be read from DRAM, decrypted in the XTS module and sent back to the host. Data is encrypted due to the write command before being sent to the DRAM. The data is decrypted due to the read command being read from the DRAM.