AM29PDL129H datasheet(22/49 Pages) SPANSION

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Am29PDL129H

November 2, 2005

Selecting a Sector Protection Mode

The device is shipped with all sectors unprotected.

AMD offers the option of programming and protecting

sectors at the factory prior to shipping the device

through AMD’s ExpressFlash™ Service. Contact an

AMD representative for details.

It is possible to determine whether a sector is pro-

tected or unprotected. See Autoselect Mode for de-

tails.

Table 9.

Sector Protection Schemes

Write Protect (WP#)

The Write Protect feature provides a hardware method

of protecting sectors without using VID. This function

is provided by the WP# pin and overrides the previ-

ously discussed High Voltage Sector Protection

method.

If the system asserts VIL on the WP#/ACC pin, the de-

vice disables program and erase functions in the two

outermost 4 Kword sectors on both ends of the flash

array independent of whether it was previously pro-

tected or unprotected.

If the system asserts VIH on the WP#/ACC pin, the de-

vice reverts to whether sectors were last set to be pro-

tected or unprotected. That is, sector protection or

unprotection for these sectors depends on whether

they were last protected or unprotected using the

method described in High Voltage Sector Protection.

Note that the WP#/ACC pin must not be left floating or

unconnected; inconsistent behavior of the device may

result.

Persistent Protection Bit Lock

The Persistent Protection Bit (PPB) Lock is a volatile

bit that reflects the state of the Password Mode Lock-

ing Bit after power-up reset. If the Password Mode

Lock Bit is also set after a hardware reset (RESET#

asserted) or a power-up reset, the ONLY means for

clearing the PPB Lock Bit in Password Protection

Mode is to issue the Password Unlock command. Suc-

cessful execution of the Password Unlock command

clears the PPB Lock Bit, allowing for sector PPBs

modifications. Asserting RESET#, taking the device

through a power-on reset, or issuing the PPB Lock Bit

Set command sets the PPB Lock Bit to a “1” when the

Password Mode Lock Bit is not set.

If the Password Mode Locking Bit is not set, including

Persistent Protection Mode, the PPB Lock Bit is

cleared after power-up or hardware reset. The PPB

Lock Bit is set by issuing the PPB Lock Bit Set com-

mand. Once set the only means for clearing the PPB

Lock Bit is by issuing a hardware or power-up reset.

The Password Unlock command is ignored in Persis-

tent Protection Mode.

High Voltage Sector Protection

Sector protection and unprotection may also be imple-

mented using programming equipment. The proce-

dure requires high voltage (VID) to be placed on the

RESET# pin. Refer to Figure 1 for details on this pro-

cedure. Note that for sector unprotect, all unprotected

sectors must first be protected prior to the first sector

write cycle.

Figure 1.

Temporary Sector Unprotect

Figure 2.

Flash Memory Region

The SecSi (Secured Silicon) Sector feature provides a

Flash memory region that enables permanent part

identification through an Electronic Serial Number

(ESN) The 128-word SecSi sector is divided into 64

factory-lockable words that can be programmed and

locked by the customer. The SecSi sector is located at

addresses 000000h-00007Fh in both Persistent Pro-

tection mode and Password Protection mode. It uses

indicator bits (DQ6, DQ7) to indicate the factory-

locked and customer-locked status of the part.

The system accesses the through a command se-

quence (see “Enter /Exit Command Sequence”). After

the system has written the Enter command sequence,

it may read the by using the addresses normally occu-

pied by the boot sectors. This mode of operation con-

tinues until the system issues the Exit command

sequence, or until power is removed from the device.

On power-up, or following a hardware reset, the device

reverts to sending commands to the normal address

space.

Factory-Locked Area (64 words)

The factory-locked area of the SecSi Sector (000000h-

00003Fh) is locked when the part is shipped, whether

or not the area was programmed at the factory. The

SecSi Sector Factory-locked Indicator Bit (DQ7) is per-

manently set to a “1”. AMD offers the ExpressFlash

service to program the factory-locked area with a ran-

dom ESN, a customer-defined code, or any combina-

Notes:

1. All protected sectors unprotected (If WP#/ACC = VIL,

sectors will remain protected).

2. All previously protected sectors are protected once

again.

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