AM29DL640D120 AMD [Advanced Micro Devices], AM29DL640D120 Datasheet - Page 17

• Manufacturer Part Number: AM29DL640D120
• Description: 64 Megabit CMOS 3.0 Volt-only, Simultaneous Read/Write Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

The alternate method intended only for programming
equipment requires V
This method is compatible with programmer routines
written for earlier 3.0 volt-only AMD flash devices.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors at its 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 the Autoselect Mode
section for details.
Write Protect (WP#)
The Write Protect function provides a hardware
method of protecting without using V
one of two provided by the WP#/ACC pin.
If the system asserts V
vice disables program and erase functions in sectors
0, 1, 140, and 141, independently of whether those
sectors were protected or unprotected using the
method described in “Sector/Sector Block Protection
and Unprotection”.
If the system asserts V
vice reverts to whether sectors 0, 1, 140, and 141
were last set to be protected or unprotected. That is,
sector protection or unprotection for these sectors de-
pen ds on w heth er they were las t pro tec te d o r
unprotected using the method described in “Sec-
tor/Sector Block Protection and Unprotection”.
Note that the WP#/ACC pin must not be left floating or
unconnected; inconsistent behavior of the device may
result.
16
WP# Input
Voltage
V
V
V
HH
IH
IL
Table 7. WP#/ACC Modes
Disables programming and erasing in
SA0, SA1, SA140, and SA141
Enables programming and erasing in
SA0, SA1, SA140, and SA141
Enables accelerated programming
(ACC). See “Accelerated Program
Operation” on page 10.
ID
IL
IH
on address pin A9 and OE#.
on the WP#/ACC pin, the de-
on the WP#/ACC pin, the de-
Device
Mode
ID
. This function is
Am29DL640D
Temporary Sector Unprotect
(Note: For the following discussion, the term “sector”
applies to both sectors and sector blocks. A sector
block consists of two or more adjacent sectors that are
protected or unprotected at the same time (see Table
6).
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RE-
SET# pin to V
formerly protected sectors can be programmed or
erased by selecting the sector addresses. Once V
removed from the RESET# pin, all the previously pro-
tected sectors are protected again. Figure 1 shows the
algorithm, and Figure 25 shows the timing diagrams,
for this feature. If the WP#/ACC pin is at V
1, 140, and 141 will remain protected during the Tem-
porary sector Unprotect mode.
Notes:
1. All protected sectors unprotected (If WP#/ACC = V
2. All previously protected sectors are protected once
Figure 1. Temporary Sector Unprotect Operation
sectors 0, 1, 140, and 141 will remain protected).
again.
ID
(8.5 V – 12.5 V). During this mode,
Unprotect Completed
Program Operations
Temporary Sector
Perform Erase or
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
ID
IH
October 7, 2004
IL
, sectors 0,
IL
ID
,
is