29F010 Ver la hoja de datos (PDF) - STMicroelectronics

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29F010

1 Mbit (128Kb x8, Uniform Block) Single Supply Flash Memory

STMicroelectronics 

M29F010B

VLKO. This prevents Bus Write operations from ac-

cidentally damaging the data during power up,

power down and power surges. If the Program/

Erase Controller is programming or erasing during

this time then the operation aborts and the memo-

ry contents being altered will be invalid.

A 0.1µF capacitor should be connected between

the VCC Supply Voltage pin and the VSS Ground

pin to decouple the current surges from the power

supply. The PCB track widths must be sufficient to

carry the currents required during program and

erase operations, ICC4.

Vss Ground. The VSS Ground is the reference

for all voltage measurements.

BUS OPERATIONS

There are five standard bus operations that control

the device. These are Bus Read, Bus Write, Out-

put Disable, Standby and Automatic Standby. See

Table 4, Bus Operations, for a summary. Typically

glitches of less than 5ns on Chip Enable or Write

Enable are ignored by the memory and do not af-

fect bus operations.

Bus Read. Bus Read operations read from the

memory cells, or specific registers in the Com-

mand Interface. A valid Bus Read operation in-

volves setting the desired address on the Address

Inputs, applying a Low signal, VIL, to Chip Enable

and Output Enable and keeping Write Enable

High, VIH. The Data Inputs/Outputs will output the

value, see Figure 8, Read Mode AC Waveforms,

and Table 11, Read AC Characteristics, for details

of when the output becomes valid.

Bus Write. Bus Write operations write to the

Command Interface. A valid Bus Write operation

begins by setting the desired address on the Ad-

dress Inputs. The Address Inputs are latched by

the Command Interface on the falling edge of Chip

Enable or Write Enable, whichever occurs last.

The Data Inputs/Outputs are latched by the Com-

mand Interface on the rising edge of Chip Enable

or Write Enable, whichever occurs first. Output En-

able must remain High, VIH, during the whole Bus

Write operation. See Figures 9 and 10, Write AC

Waveforms, and Tables 12 and 13, Write AC

Characteristics, for details of the timing require-

ments.

Output Disable. The Data Inputs/Outputs are in

the high impedance state when Output Enable is

High, VIH.

Standby. When Chip Enable is High, VIH, the

Data Inputs/Outputs pins are placed in the high-

impedance state and the Supply Current is re-

duced to the Standby level.

When Chip Enable is at VIH the Supply Current is

reduced to the TTL Standby Supply Current ICC2.

To further reduce the Supply Current to the CMOS

Standby Supply Current, ICC3, Chip Enable should

be held within VCC ± 0.2V. For Standby current

levels see Table 10, DC Characteristics.

During program or erase operations the memory

will continue to use the Program/Erase Supply

Current, ICC4, for Program or Erase operations un-

til the operation completes.

Automatic Standby. If CMOS levels (VCC ± 0.2V)

are used to drive the bus and the bus is inactive for

150ns or more the memory enters Automatic

Standby where the internal Supply Current is re-

duced to the CMOS Standby Supply Current, ICC3.

The Data Inputs/Outputs will still output data if a

Bus Read operation is in progress.

Special Bus Operations

Additional bus operations can be performed to

read the Electronic Signature and also to apply

and remove Block Protection. These bus opera-

tions are intended for use by programming equip-

ment and are not usually used in applications.

They require VID to be applied to some pins.

Electronic Signature. The memory has two

codes, the manufacturer code and the device

code, that can be read to identify the memory.

These codes can be read by applying the signals

listed in Table 4, Bus Operations.

Block Protection and Blocks Unprotection. Each

block can be separately protected against acci-

dental Program or Erase. Protected blocks can be

unprotected to allow data to be changed. Block

Protection and Blocks Unprotection operations

must only be performed on programming equip-

ment. For further information refer to Application

Note AN1122, Applying Protection and Unprotec-

tion to M29 Series Flash.

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