SST38VF6402 datasheet(10/66 Pages) MICROCHIP

10 / 66 page

DS20005015D

64 Mbit (x16) Advanced Multi-Purpose Flash Plus

SST38VF6401 / SST38VF6402 / SST38VF6403 / SST38VF6404

During the Program operation, the only valid reads are Data# Polling, Toggle Bits, and RY/BY#. During

the internal Program operation, the host is free to perform additional tasks. Any commands issued

during the internal Program operation are ignored. During the command sequence, WP# should be

statically held high or low.

When programming more than a few words, Microchip recommends Write-Buffer Programming.

Write-Buffer Programming

The SST38VF6401/6402/6403/6404 offer Write-Buffer Programming, a feature that enables faster

effective word programming. To use this feature, write up to 16 words with the Write-to-Buffer com-

mand, then use the Program Buffer-to-Flash command to program the Write-Buffer to memory.

The Write-to-Buffer command consists of between 5 and 20 write cycles. The total number of write

cycles in the Write-to-Buffer command sequence is equal to the number of words to be written to the

buffer plus four.

The first three cycles in the command sequence tell the device that a Write-to-Buffer operation will

begin.

The fourth cycle tells the device the number of words to be written into the buffer and the block

address of these words. Specifically, the write cycle consists of a block address and a data value called

the Word Count (WC), which is the number of words to be written to the buffer minus one. If the WC is

greater than 15, the maximum buffer size minus 1, then the operation aborts.

For the fifth cycle, and all subsequent cycles of the Write-to-Buffer command, the command sequence

consists of the addresses and data of the words to be written into the buffer. All of these cycles must

have the same A21 - A4 address, otherwise the operation aborts. The number of Write cycles required

is equal to the number of words to be written into the Write-Buffer, which is equal to WC plus one. The

correct number of Write cycles must be issued or the operation will abort. Each Write cycle decrements

the Write-Buffer counter, even if two or more of the Write cycles have identical address values. Only

the final data loaded for each buffer location is held in the Write-Buffer.

Once the Write-to-Buffer command sequence is completed, the Program Buffer-to-Flash command

should be issued to program the Write-Buffer contents to the specified block in memory. The block

address (i.e. A21 - A15) in this command must match the block address in the 4th write cycle of the

Write-to-Buffer command or the operation aborts. See Table 11 for details on Write-to-Buffer and Pro-

gram-Buffer-to-Flash commands.

While issuing these command sequences, the Write-Buffer Programming Abort detection bit (DQ1)

indicates if the operation has aborted. There are several cases in which the device can abort:

•

In the fourth write cycle of the Write-to-Buffer command, if the WC is greater than 15, the opera-

tion aborts.

•

In the fifth and all subsequent cycles of the Write-to-Buffer command, if the address values, A21 -

A4, are not identical, the operation aborts.

•

If the number of write cycles between the fifth to the last cycle of the Write-to-Buffer command is

greater than WC +1, the operation aborts.

•

After completing the Write-to-Buffer command sequence, issuing any command other than the

Program Buffer-to-Flash command, aborts the operation.

•

Loading a block address, i.e. A21-A15, in the Program Buffer-to-Flash command that does not

match the block address used in the Write-to-Buffer command aborts the operation.

SST38VF6402 bảng dữ liệu(PDF) 10 Page - Microchip Technology

SST38VF6402 bảng dữ liệu(HTML) 10 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

bảng dữ liệu tải về

Link URL