MBM29BS32LF-18 查看數據表（PDF） - Spansion Inc.
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MBM29BS32LF-18 Datasheet PDF : 60 Pages
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MBM29BS/BT32LF-18/25
Automatic Sleep Mode
Automatic sleep mode works to restrain power consumption during read-out of the device data. This mode can
be useful in the application such as a handy terminal which requires low power consumption.
While in asynchronous mode, the device automatically enables this mode when addresses remain stable for
tACC +60 ns. While in synchronous mode, the device automatically enables this mode when either the first active
CLK level is greater than tACC or the CLK runs slower than 5 MHz. A new burst operations is required to provid
new data. It is not necessary to control CE, WE, and OE on this mode. Under the mode, the current consumed
is typically 0.2 µA (CMOS Level)(ICC5).
During simultaneous operation, VCC active current (ICC2) is required.
Since the data are latched during this mode, the data are continuously read out. When the addresses are
changed, the mode is automatically canceled and the device reads the data for changed addresses.
Output Disable
When the OE input is at VIH, output from the device is disabled. The outputs are placed in the high impedance
state.
Autoselect Mode
The Autoselect mode allows the reading out of a binary code and identifies its manufacturer and type.It is intended
for use by programming equipment for the purpose of automatically matching the device to be programmed with
its corresponding programming algorithm. This mode is functional over the entire temperature range of the
device. Autoselect may only be entered and used when in the asynchronous mode.
The manufacturer and device codes can be read via the command register, Three identifier bytes may then be
sequenced from the device outputs by toggling addresses. All addresses are DON’T CARES except A7 to A0.
(See “MBM29BS/BT32LF User Bus Operations Table” in sDEVICE BUS OPERATIONS.)
The command sequence is illustrated in “MBM29BS/BT32LF Command Definitions Table” (in sDEVICE BUS
OPERATIONS). (Refer to Autoselect Command section.)
In the command Autoselect mode, the bank addresses BA; (A20, A19)must point to a specific bank during the
third write bus cycle of the Autoselect command. Then the Autoselect data will be read from that bank while
array data can be read from the other bank.
A read cycle from address 00h returns the manufacturer’s code (Fujitsu=04h) . A read cycle at address 01h
outputs device code. When 227Eh is output, it indicates that two additional codes, called Extended Device Codes
will be required. Therefore the system may continue reading out these Extended Device Codes at addresses of
0Eh and 0Fh. (Refer to “MBM29BS/BT32LF Sector Protection Verify Autoselect Codes Table” and “Expanded
Autoselect Code Table” in sDEVICE BUS OPERATIONS. )
Write
Device erasure and programming are accomplished via the command register. The contents of the register serve
as input to the internal state machine. The state machine output dictates the function of the device.
The command register itself does not occupy any addressable memory location. The register is a latch used to
store the commands, along with the address and data information needed to execute the command.
The device has the capability of performing programming operations. It has inputs/outputs that accept both
address and data information. During a program operation(AVD latched address)(Program2), the command
register is written by bringing active CLK edge while AVD and CE to VIL, and OE to VIH when providing an address
to the device, addresses are latched on the CLK active edge or AVD rising edge(when CLK active edge doesn’t
appear while AVD=VIL) and drive WE and CE to VIL, and OE to VIH, data is latched on the rising edge of WE.
During a program operation(WE latched address)(Program1), the command register is written by bringing WE
to VIL, while CE is at VIL and OE is at VIH. Addresses are latched on the falling edge of WE or CE, whichever
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