TMS28F008AXY datasheet(20/52 Pages) TI

20 / 52 page

TMS28F008Axy,TMS28F800Axy

1 048 576 BY 8-BIT/524 288 BY 16-BIT

AUTO-SELECT BOOT-BLOCK FLASH MEMORIES

SMJS851A – NOVEMBER 1997 – REVISED MARCH 1998

POST OFFICE BOX 1443

• HOUSTON, TEXAS 77251–1443

automatic power-saving mode

Substantial power savings are realized during periods when the array is not being read. During this time, the

device switches to the automatic power-saving (APS) mode. When the device switches to this mode, ICC

reduces by an order of magnitude. For example, for a 5 V port, ICC typically reduces from 40 mA to 1 mA. The

low level of power is maintained until another read operation is initiated. In this mode, the I/O pins retain the data

from the last memory address read until a new address is read. This mode is entered automatically if no new

address is accessed within a 200-ns time-out period.

reset/deep power-down mode

Very low levels of power consumption can be attained by using a special pin, RP, to disable internal device

circuitry. When RP is at a CMOS logic-low level of 0.0 V

± 0.2 V, a much lower ICC value or power is achievable.

This is important in portable applications where extended battery life is of major concern.

A recovery time is required when exiting from deep power-down mode. For a read-array operation, a

minimum of td(RP) is required before data is valid, and a minimum of trec(RPHE) and trec(RPHW) in deep

power-down mode is required before data input to the CSM can be recognized. With RP at ground, the WSM

is reset and the status register is cleared, effectively eliminating accidental programming to the array during

system reset. After restoration of power, the device does not recognize any operation command until RP is

returned to a VIH or VHH level.

Should RP go low during a program or erase operation, the device powers down and, therefore, becomes

nonfunctional. Data being written or erased at that time becomes invalid or indeterminate, requiring that the

operation be performed again after power restoration.

TMS28F008AXY Datasheet(PDF) 20 Page - Texas Instruments