A29L008TV-70 查看數據表（PDF） - AMIC Technology

零件编号

产品描述 (功能)

生产厂家

A29L008TV-70

1M X 8 Bit CMOS 3.0 Volt-only, Boot Sector Flash Memory

AMIC Technology 

A29L008 Series

Sector Protection/Unprotection

The hardware sector protection feature disables both

program and erase operations in any sector. The hardware

sector unprotection feature re-enables both program and

erase operations in previously protected sectors.

It is possible to determine whether a sector is protected or

unprotected. See “Autoselect Mode” for details.

Sector protection / unprotection can be implemented via two

methods. The primary method requires VID on the

RESETpin only, and can be implemented either in-system or

via programming equipment. Figure 2 shows the algorithm

and the Sector Protect / Unprotect Timing Diagram illustrates

the timing waveforms for this feature. This method uses

standard microprocessor bus cycle timing. For sector

unprotect, all unprotected sectors must first be protected

prior to the first sector unprotect write cycle. The alternate

method must be implemented using programming

equipment. The procedure requires a high voltage (VID) on

address pin A9 and the control pins.

The device is shipped with all sectors unprotected.

It is possible to determine whether a sector is protected or

unprotected. See "Autoselect Mode" for details.

Hardware Data Protection

The requirement of command unlocking sequence for

programming or erasing provides data protection against

inadvertent writes (refer to the Command Definitions table).

In addition, the following hardware data protection measures

prevent accidental erasure or programming, which might

otherwise be caused by spurious system level signals during

VCC power-up transitions, or from system noise. The device is

powered up to read array data to avoid accidentally writing

data to the array.

Write Pulse "Glitch" Protection

Noise pulses of less than 5ns (typical) on OE , CE or WE

do not initiate a write cycle.

Logical Inhibit

Write cycles are inhibited by holding any one of OE =VIL,

CE = VIH or WE = VIH. To initiate a write cycle, CE and

WE must be a logical zero while OE is a logical one.

Power-Up Write Inhibit

If WE = CE = VIL and OE = VIH during power up, the

device does not accept commands on the rising edge of

WE . The internal state machine is automatically reset to

reading array data on the initial power-up.

Temporary Sector Unprotect

This feature allows temporary unprotection of previous

protected sectors to change data in-system. The Sector

Unprotect mode is activated by setting the RESET pin to VID.

During this mode, formerly protected sectors can be

programmed or erased by selecting the sector addresses.

Once VID is removed from the RESET pin, all the previously

protected sectors are protected again. Figure 1 shows the

algorithm, and the Temporary Sector Unprotect diagram

shows the timing waveforms, for this feature.

START

RESET = VID

(Note 1)

Perform Erase or

Program Operations

RESET = VIH

Temporary Sector

Unprotect

Completed (Note 2)

Notes:

1. All protected sectors unprotected.

2. All previously protected sectors are protected once again.

Figure 1. Temporary Sector Unprotect Operation

PRELIMINARY (November, 2002, Version 0.0)

10

AMIC Technology, Corp.

Share Link: