OneNAND512Mb(KFG1216U2B-xIB6)
FLASH MEMORY
3.7
Read Operation
See Timing Diagrams 6.1, 6.2, 6.5, 6.6, 6.7 and 6.8
The device has two read modes; Asynchronous Read and Synchronous Burst Read.
The initial state machine automatically sets the device into the Asynchronous Read Mode (RM=0) to prevent the spurious altering of
memory content upon device power up or after a Hardware reset. No commands are required to retrieve data in Asynchronous Read
Mode.
The Synchronous Read Mode is enabled by setting RM bit of System Configuration1 Register (F221h) to
Synchronous Read Mode (RM=1). See Section 2.8.19 for more information about System Configuration1 Register.
3.7.1 Asynchronous Read Mode Operation (RM=0, WM=0)
See Timing Diagrams 6.5, 6.6, 6.7 and 6.8
In an Asynchronous Read Mode, data is output with respect to a logic input, AVD.
Output data will appear on DQ15-DQ0 when a valid address is asserted on A15-A0 while driving AVD and CE to VIL. WE is held at
VIH. The function of the AVD signal is to latch the valid address.
Address access time from AVD low (tAA) is equal to the delay from valid addresses to valid output data.
The Chip Enable access time (tCE) is equal to the delay from the falling edge of CE to valid data at the outputs.
The Output Enable access time (tOE) is the delay from the falling edge of OE to valid data at the output.
3.7.2 Synchronous Read Mode Operation (RM=1, WM=X)
See Timing Diagrams 6.1 and 6.2
In a Synchronous Read Mode, data is output with respect to a clock input.
The device is capable of a continuous linear burst operation and a fixed-length linear burst operation of a preset length. Burst
address sequences for continuous and fixed-length burst operations are shown in the table below.
Burst Address Sequences
Burst Address Sequence(Decimal)
Start
Addr.
Continuous Burst
0-1-2-3-4-5-6-..-0-1...
1-2-3-4-5-6-7-..-1-2...
2-3-4-5-6-7-8-..-2-3...
4-word Burst
0-1-2-3-0...
1-2-3-0-1...
2-3-0-1-2...
8-word Burst
16-word Burst
32-word Burst
0
1
2
0-1-2-3-4-5-6-7-0...
1-2-3-4-5-6-7-0-1...
2-3-4-5-6-7-0-1-2...
0-1-2-3-4-....-13-14-15-0... 0-1-2-3-4-....-29-30-31-0...
1-2-3-4-5-....-14-15-0-1...
2-3-4-5-6-....-15-0-1-2...
1-2-3-4-5-....-30-31-0-1...
2-3-4-5-6-....-31-0-1-2...
Wrap
around
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In the burst mode, the initial word will be output asynchronously, regardless of BRWL. While the following words will be determined by
BRWL value.
The latency is determined by the host based on the BRWL bit setting in the System Configuration 1 Register. The default BRWL is 4
latency cycles. At clock frequencies of 40MHz or lower, latency cycles can be reduced to 3. BRWL can be set up to 7 latency cycles.
The BRWL registers can be read during a burst read mode by using the AVD signal with an address.
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