Samsung FLEX-MUXONENAND KFN8GH6Q4M - Manual (Page 103)

Flex-MuxOneNAND4G(KFM4GH6Q4M-DEBx)
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FLASH MEMORY
Flex-MuxOneNAND8G(KFN8GH6Q4M-DEBx)
Flex-MuxOneNAND16G(KFKAGH6Q4M-DEBx)
3.14 DQ6 Toggle Bit
The Flex-MuxOneNAND device has DQ6 Toggle bit. Toggle bit is another option to detect whether an internal load operation is in progress or
completed. Once the BufferRAM(BootRAM, DataRAM0, DataRAM1) is at a busy state during internal load operation, DQ6 will toggle. Toggling
DQ6 will stop after the device completes its internal load operation. The Flex-MuxOneNAND device’s DQ6 Toggle will be valid only when host
reads BufferRAM which will be loaded by internal load operation. DQ6 toggle can be used 350ns after load command(0000h of Command
based Operation) issue, until data sensing from the NAND Flash Array memory into Page Buffer and transferring from the Page Buffer to the
DataRAM are finished. By reading the same address more than twice utilizing asynchronous read (Figure 6.20, 6.21), the host will read tog-
gled value of DQ6 and the rest of DQ’s are not guaranteed to be fixed value. DQ6 toggle is only for reading status of BufferRAM which is being
loaded by internal operation, that is, BufferRAM.
DQ6 toggle bit can be useful at Cold Reset to determine the ready/busy state of Flex-MuxOneNAND. Since INT pin is initially at High-Z state,
when host needs to check the completion of boot code copy operation, the host cannot judge the ready/busy status of Flex-MuxOneNAND by
INT pin. Therefore, by checking DQ6 toggle of BootRAM, the host should detect the completion of boot code copy.
Status DQ15~DQ7 DQ6 DQ5~DQ0
In Progress Data Loading X (Don’t Care) Toggle X (Don’t Care)