FAQs
| function | setting | explanation |
|---|---|---|
| Cache Read | RM=X, WM=X | This operation is available both synchronously and asynchronously. Read performance is improved by hiding the time taken by setting address and the time taken by transferring data from page buffer to DataRAM. |
| Block Read | RM=1, WM=X | Once setting 'Start page address (FPA)' and 'Number of Page (FPC)', the host can read consecutive pages within a block without other address settings. It sets the processor free because OneNAND counts the page address automatically. This leads to read per |
| Sync. Write Mode |
RM=1, WM=1 | Synchronous burst write is available with the 1 Gb(A) device while past devices can be operated with 'Asynchronous Write' only. Write performance improves with this operation. |
n 1 Gb(A), the '1st block OTP' feature is added while there was only one OTP block on the past devices. Users can employ the 1st block in the NAND core as an OTP block with this feature. The way to lock the block is described below. Once the lock bit is programmed, it can't be modified. And locking the OTP block and the 1st block OTP must be executed at the same time. According to this method of setting lock bits, there could be three cases as following: 1) Only OTP block locked, 2) Only 1st block OTP locked, 3) Both OTP and 1st block OTP locked. If you want to get more details, please refer to the datasheet.
Read operations can be executed within a chip at one time. So, if DBS or DFS is changed, the operation won't be guaranteed.
After the device is cold reset, all blocks are locked. To program/erase/load, the targeted block should be unlocked to be operated. On past devices, hosts had to unlock block by block to operate. Since the 'All block unlock' operation is supported in the 1Gb(A) device, the host can execute program/erase/load easily without burden to the unlock block by block. If some blocks are 'lock-tight', the blocks will not be unlocked, even if 'All block unlock' is executed. The blocks will be 'lock' only when cold reset. If the 1st block is set as the 'OTP block', it will keep its state as the 'lock' even when an 'unlock' operation is executed.
