FM21L16_11 RAMTRON [Ramtron International Corporation], FM21L16_11 Datasheet - Page 6

• Manufacturer Part Number: FM21L16_11
• Description: 2Mbit F-RAM Memory
• Manufacturer: RAMTRON [Ramtron International Corporation]

reduced by requiring three more write cycles, one that
requires an exact inversion of the data byte. A flow
chart of the entire write protect operation is shown in
For example, the following sequence write-protects addresses from 0C000h to 13FFFh (sectors 3 & 4):
Rev. 2.0
Apr. 2011
Read
Read
Read
Read
Read
Read
Write 1DAAAh
Write 0ECCCh
Write 0FF00h
Read
Address
12555h
1DAAAh
01333h
0ECCCh
000FFh
1FF00h
00000h
Data
18h
E7h
-
-
-
-
-
-
-
-
Figure 3. Write-Protect State Machine
; Data is don’t care
; return to Normal Operation
; bits 3 & 4 = 1
; complement of 18h
Figure 3. The write-protect settings are nonvolatile.
The factory default: all blocks are unprotected.
FM21L16 - 128Kx16 FRAM
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