Semiconductor memory system and data writing method

A semiconductor memory system comprising:

• a NOR flash memory including a plurality of memory cells to which a plurality of blocks, each having a plurality of pages, is assigned;
• and
• a write control portion configured to receive consecutive write data pieces, and to store said write data pieces in said memory cells for each of the blocks, wherein said write control portion includes:
• a write page address storage configured to store, when it receives a write page address, the received write page address;
• a page address collator configured to determine, on the basis of the data addresses indicative of write bit positions in each of the blocks, a page address of a page in one of the blocks for writing each of said write data pieces and to output the determined page address as the write page address to said write page address storage when the determined page address is not stored in said write page address storage;
• an output part configured to sequentially read write page addresses stored in said write page address storage and to output the read write page addresses;
• a write buffer configured to incorporate at least one of said write data pieces into each of page data pieces indicated by the read write page addresses among first page data pieces corresponding to the plurality of pages respectively, and to output the page data pieces having said write data pieces incorporated therein;
• an ECC part configured to apply an error-correction encoding process to each of said page data pieces output by said write buffer to obtain encoded write data pieces, while ignoring each remaining page data piece other than the page data pieces having said write data pieces incorporated, among said first page data pieces;
• and
• a decoder configured to apply a writing voltage based on each of said encoded write data pieces to each of the memory cells belonging to the pages indicated by the read write page addresses.