MBM29DL800BA-70PBT-SF2 Просмотр технического описания (PDF) - Spansion Inc.

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MBM29DL800BA-70PBT-SF2

8M (1M X 8/512K X 16) BIT

Spansion Inc. 

MBM29DL800TA-70/90/MBM29DL800BA-70/90

s COMMAND DEFINITIONS

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

Writing incorrect address and data values or writing them in the improper sequence will reset the devices to the

read mode. Some commands are required Bank Address (BA) input. When command sequences are inputed

to bank being read, the commands have priority than reading. “MBM29DL800TA/BA Command Definitions Table”

in sDEVICE BUS OPERATION 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 bank address (BA) and the Autoselect command. Then the manufacture and device

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

Following the command write, a read cycle from address (BA)00h retrieves the manufacture code of 04h. A read

cycle from address (BA)01h for ×16((BA)02h for ×8) returns the device code (MBM29DL800TA = 4Ah and

MBM29DL800BA = CBh for ×8 mode; MBM29DL800TA = 224Ah and MBM29DL800BA = 22CBh for ×16 mode).

(See “MBM29DL800TA/BA Sector Protection Verify Autoselect Codes Table” and “Extended Autoselect Code

Table” in sDEVICE BUS OPERATION.)

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 (BA)02h for ×16 ((BA)04h for ×8). Scanning the sector addresses

(A18, A17, A16, A15, A14, A13, and A12) while (A6, A1, A0) = (0, 1, 0) will produce a logical “1” at device output DQ0

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

protected sector. (See “MBM29DL800TA/BA User Bus Operations Tables (BYTE = VIH and BYTE = VIL)” in

sDEVICE BUS OPERATION.)

The manufacture and device codes can be allowed reading from selected bank. To read the manufacture and

device codes and sector protection status from non-selected bank, it is necessary to write Read/Reset command

sequence into the register and then Autoselect command should be written into the bank to be read.

If the software (program code) for Autoselect command is stored into the Frash memory, the device and

manufacture codes should be read from the other bank where is not contain the software.

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