29LV650 View Datasheet(PDF) - Fujitsu

Part Name

Description

Manufacturer

29LV650

FLASH MEMORY CMOS 64M (4M x 16) BIT

Fujitsu 

MBM29LV650UE/651UE-90/12

s COMMAND DEFINITIONS

Device operations are selected by writing specific address and data sequences into the command register.

Writing incorrect data values or writing them in the improper sequence will reset the devices to the read mode.

Table 3 defines the valid register command sequences. Note that the Erase Suspend (B0h) and Erase Resume

(30h) commands are valid only while the Sector Erase operation is in progress. Moreover both Read/Reset

commands are functionally equivalent, resetting the device to the read mode. Please note that commands are

always written at DQ0 to DQ7 and DQ8 to DQ15 bits are ignored.

Read/Reset Command

In order to return from Autoselect mode or Exceeded Timing Limits (DQ5 = 1) to Read/Reset mode, the Read/

Reset operation is initiated by writing the Read/Reset command sequence into the command register.

Microprocessor read cycles retrieve array data from the memory. The devices remain enabled for reads until the

command register contents are altered.

The devices will automatically power-up in the Read/Reset state. In this case, a command sequence is not

required to read data. Standard microprocessor read cycles will retrieve array data. This default value ensures

that no spurious alteration of the memory content occurs during the power transition. Refer to the AC Read

Characteristics and Waveforms for the specific timing parameters.

Autoselect Command

Flash memories are intended for use in applications where the local CPU alters memory contents. As such,

manufacture and device codes must be accessible while the devices reside in the target system. PROM

programmers typically access the signature codes by raising A9 to a high voltage. However, multiplexing high

voltage onto the address lines is not generally desired system design practice.

The device contains an Autoselect command operation to supplement traditional PROM programming

methodology. The operation is initiated by writing the Autoselect command sequence into the command register.

The Autoselect command sequence is initiated by first writing two unlock cycles. This is followed by a third write

cycle that contains the address and the Autoselect command. Then the manufacture and device codes can be

read from the address, and an actual data of memory cell can be read from the another address.

Following the command write, a read cycle from address XX00h retrieves the manufacture code of 04h. A read

cycle from address XX01h returns the device code (MBM29LV650UE/651UE = 22D7h). A read cycle from

address XX03h returns the Extended Code (MBM29LV650UE = 0010h, MBM29LV651UE = 0000h). (See Tables

4.1 and 4.2.)

All manufacturer and device codes will exhibit odd parity with DQ7 defined as the parity bit. Sector state (protection

or unprotection) will be informed by address XX02h. Scanning the sector group addresses (A21, A20, A19, A18,

and A17) while (A6, A1, A0) = (0, 1, 0) will produce a logical “1” at device output DQ0 for a protected sector group.

The programming verification should be performed by verify sector group protection on the protected sector.

(See Table 2.)

To terminate the operation, it is necessary to write the Read/Reset command sequence into the register, and

also to write the Autoselect command during the operation, execute it after writing Read/Reset command

sequence.

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