Electronic Components Datasheet Search
Selected language     English  ā–¼
Advanced Search

              



Part Name


FM25040A Datasheet(PDF) 5 Page - Ramtron International Corporation

Part No. FM25040A
Description  4Kb FRAM Serial Memory
Download  13 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  RAMTRON [Ramtron International Corporation]
Homepage  http://www.ramtron.com
Logo 

 
 5 page
background image
FM25040A
Rev. 3.0
May 2006
Page 5 of
13
Data Transfer
All data transfers to and from the FM25040A occur
in 8-bit groups. They are synchronized to the clock
signal (SCK) and they transfer most significant bit
(MSB) first. The serial input data is clocked in on
the rising edge of SCK. The serial data output is
driven from the falling edge of SCK.
Command Structure
There are six commands called op-codes that can be
issued by the bus master to the FM25040A. They are
listed in the table below. These op-codes control the
functions performed by the memory. They can be
divided
into
three
categories.
First,
there
are
commands that have no subsequent data transfer.
They perform a single function, such as, enabling a
write operation. Second are commands followed by
one byte, either in or out. They operate on the status
register.
Third
are
commands
for
memory
transactions followed by address and one or more
bytes of data.
Table 1. Op-code Commands
Name
Description
Op-code
WREN
Set Write Enable Latch
0000_0110b
WRDI
Write Disable
0000_0100b
RDSR
Read Status Register
0000_0101b
WRSR
Write Status Register
0000_0001b
READ
Read Memory Data
0000_A011b
WRITE
Write Memory Data
0000_A010b
WREN - Set Write Enable Latch
The FM25040A will power up with writes disabled.
The WREN command must be issued prior to any
write operation. Sending the WREN op-code will
allow the user to issue subsequent op-codes for
write operations. These include writing the status
register and writing the memory.
Sending the WREN op-code causes the internal
Write Enable Latch to be set. A flag bit in the status
register, called WEL, indicates the state of the latch.
WEL=1 indicates that writes are permitted. A write
to the status register has no effect on the WEL bit.
Completing any write operation will automatically
clear the write-enable latch and prevent further
writes without another WREN command. Figure 5
below
illustrates
the
WREN
command
bus
configuration.
WRDI - Write Disable
The WRDI command disables all write activity by
clearing the Write Enable Latch. The user can verify
that writes are disabled by reading the WEL bit in
the status register and verifying that WEL=0. Figure
6 illustrates the WRDI command bus configuration.
Figure 6. WRDI Bus Configuration
Figure 5. WREN Bus Configuration




Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13 


Datasheet Download



Related Electronics Part Number

Part NumberComponents DescriptionHtml ViewManufacturer
FM24C04A_054Kb FRAM Serial Memory 1 2 3 4 5 MoreRamtron International Corporation
FM24CL04_054Kb FRAM Serial Memory 1 2 3 4 5 MoreRamtron International Corporation
FM25CL04_054Kb FRAM Serial 3V Memory 1 2 3 4 5 MoreRamtron International Corporation
W25X101M-BIT 2M-BIT 4M-BIT AND 8M-BIT SERIAL FLASH MEMORY WITH 4KB SECTORS AND DUAL OUTPUT SPI 1 2 3 4 5 MoreWinbond
W25X10_071M-BIT 2M-BIT 4M-BIT AND 8M-BIT SERIAL FLASH MEMORY WITH 4KB SECTORS AND DUAL OUTPUT SPI 1 2 3 4 5 MoreWinbond
FM25CL64_0764Kb FRAM Serial 3V Memory 1 2 3 4 5 MoreRamtron International Corporation
FM24C16A_0516Kb FRAM Serial Memory 1 2 3 4 5 MoreRamtron International Corporation
FM24C64_0564Kb FRAM Serial Memory 1 2 3 4 5 MoreRamtron International Corporation
FM24CL6464Kb 2.7V-3.6V FRAM Serial Memory 1 2 3 4 5 MoreList of Unclassifed Manufacturers
FM24C256_05256Kb FRAM Serial Memory 1 2 3 4 5 MoreRamtron International Corporation

Link URL

Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Bookmark   |   Link Exchange   |   Manufacturer List
All Rights ReservedĀ© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl