NAND01G-B2C datasheet(25/67 Pages) NUMONYX

25 / 67 page

NAND01G-B2C

Device operations

25/67

6.2

Cache read

The cache read operation is used to improve the read throughput by reading data using the

cache register. Since the device has only one cache register, serial data output on one page

may be executed while data from another page is read into the cache register.

A Page Read command must be issued prior to the Sequential or Random Cache Read

command in a cache read sequence. The Cache Read command can be issued only after

the read function is complete (SR6 = ‘1’).

A cache read operation consists of three steps (see Table 10: Commands):

One bus cycle is required to setup the Cache Read command (the same as the

standard Read command)

Four (refer to Table 6 and Table 7) bus cycles are then required to input the start

address. If the host does not enter an address, the next sequential page is read.

One bus cycle is required to issue the Cache Read Confirm command to start the

P/E/R controller.

The start address must be at the beginning of a page (column address = 00h, see Table 8

and Table 9). This allows the data to be output uninterrupted after the latency time (tBLBH1),

see Figure 10.

The Ready/Busy signal can be used to monitor the start of the operation. During the latency

period the Ready/Busy signal goes Low, after this the Ready/Busy signal goes High, even if

the device is internally downloading page n+1.

Once the cache read operation has started, the status register can be read using the Read

Status Register command.

During the operation, SR5 can be read, to find out whether the internal reading is ongoing

(SR5 = ‘0’), or has completed (SR5 = ‘1’), while SR6 indicates whether the cache register is

ready to download new data.

To exit the cache read operation an Exit Cache Read command must be issued (see

Table 10).

After the device has internally read page n, the user is allowed to download data of that

page by toggling R, but the device will not trigger internally the reading of a next page.

NAND01G-B2C Datasheet(PDF) 25 Page - Numonyx B.V