Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

FM25CL04 Fiches technique(PDF) 3 Page - Ramtron International Corporation

No de pièce FM25CL04
Description  4Kb FRAM Serial 3V Memory
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  RAMTRON [Ramtron International Corporation]
Site Internet  http://www.ramtron.com
Logo RAMTRON - Ramtron International Corporation

FM25CL04 Fiches technique(HTML) 3 Page - Ramtron International Corporation

  FM25CL04 Datasheet HTML 1Page - Ramtron International Corporation FM25CL04 Datasheet HTML 2Page - Ramtron International Corporation FM25CL04 Datasheet HTML 3Page - Ramtron International Corporation FM25CL04 Datasheet HTML 4Page - Ramtron International Corporation FM25CL04 Datasheet HTML 5Page - Ramtron International Corporation FM25CL04 Datasheet HTML 6Page - Ramtron International Corporation FM25CL04 Datasheet HTML 7Page - Ramtron International Corporation FM25CL04 Datasheet HTML 8Page - Ramtron International Corporation FM25CL04 Datasheet HTML 9Page - Ramtron International Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 3 / 12 page
background image
N
O
T
R
EC
O
M
ME
N
D
ED
FO
R
N
EW
D
ES
IG
N
S
R
ep
la
ce
d
by
FM
25
L0
4
Rev. 3.1
May 2005
Page 3 of 12
Overview
The FM25CL04 is a serial FRAM memory. The
memory array is logically organized as 512 x 8 and is
accessed using an industry standard Serial Peripheral
Interface or SPI bus. Functional operation of the
FRAM is similar to serial EEPROMs. The major
difference between the FM25CL04 and a serial
EEPROM with the same pinout is the FRAM’s
superior write performance and power consumption.
Memory Architecture
When accessing the FM25CL04, the user addresses
512 locations of 8 data bits each. These data bits are
shifted serially. The addresses are accessed using the
SPI protocol, which includes a chip select (to permit
multiple devices on the bus), an op-code, and an
address. The upper address bit is included in the op-
code. The complete address of 9-bits specifies each
byte address uniquely.
Most
functions
of
the
FM25CL04
either
are
controlled by the SPI interface or are handled
automatically by on-board circuitry. The access time
for memory operation is essentially zero, beyond the
time needed for the serial protocol. That is, the
memory is read or written at the speed of the SPI bus.
Unlike an EEPROM, it is not necessary to poll the
device for a ready condition since writes occur at bus
speed. So, by the time a new bus transaction can be
shifted into the device, a write operation will be
complete. This is explained in more detail in the
interface section.
Users expect several obvious system benefits from
the FM25CL04 due to its fast write cycle and high
endurance as compared with EEPROM. In addition
there are less obvious benefits as well. For example
in a high noise environment, the fast-write operation
is less susceptible to corruption than an EEPROM
since it is completed quickly. By contrast, an
EEPROM
requiring
milliseconds
to
write
is
vulnerable to noise during much of the cycle.
Note
that
the
FM25CL04
contains
no
power
management circuits other than a simple internal
power-on reset. It is the user’s responsibility to
ensure that VDD is within datasheet tolerances to
prevent incorrect operation.
Serial Peripheral Interface – SPI Bus
The
FM25CL04
employs
a
Serial
Peripheral
Interface (SPI) bus. It is specified to operate at speeds
up to 20 MHz. This high-speed serial bus provides
high performance serial communication to a host
microcontroller.
Many common
microcontrollers
have hardware SPI ports allowing a direct interface.
It is quite simple to emulate the port using ordinary
port pins for microcontrollers that do not. The
FM25CL04 operates in SPI Mode 0 and 3.
The SPI interface uses a total of four pins: clock,
data-in, data-out, and chip select. It is possible to
connect the two data pins together. Figure 2
illustrates a typical system configuration using the
FM25CL04 with a microcontroller that offers an SPI
port. Figure 3 shows a similar configuration for a
microcontroller that has no hardware support for the
SPI bus.
Protocol Overview
The SPI interface is a synchronous serial interface
using clock and data pins. It is intended to support
multiple devices on the bus. Each device is activated
using a chip select. Once chip select is activated by
the bus master, the FM25CL04 will begin monitoring
the clock and data lines. The relationship between the
falling edge of /CS, the clock and data is dictated by
the SPI mode. The device will make a determination
of the SPI mode on the falling edge of each chip
select. While there are four such modes, the
FM25CL04 supports modes 0 and 3. Figure 4 shows
the required signal relationships for modes 0 and 3.
For both modes, data is clocked into the FM25CL04
on the rising edge of SCK and data is expected on the
first rising edge after /CS goes active. If the clock
begins from a high state, it will fall prior to beginning
data transfer in order to create the first rising edge.
The SPI protocol is controlled by op-codes. These
op-codes specify the commands to the device. After
/CS is activated the first byte transferred from the bus
master is the op-code. Following the op-code, any
addresses and data are then transferred.
Certain op-codes are commands with no subsequent
data transfer. The /CS must go inactive after an
operation is complete and before a new op-code can
be issued. There is one valid op-code only per active
chip select.


Numéro de pièce similaire - FM25CL04

FabricantNo de pièceFiches techniqueDescription
logo
List of Unclassifed Man...
FM25CL04 ETC-FM25CL04 Datasheet
98Kb / 11P
   4Kb FRAM Serial 3V Memory
FM25CL04-S ETC-FM25CL04-S Datasheet
98Kb / 11P
   4Kb FRAM Serial 3V Memory
More results

Description similaire - FM25CL04

FabricantNo de pièceFiches techniqueDescription
logo
List of Unclassifed Man...
FM25CL04 ETC-FM25CL04 Datasheet
98Kb / 11P
   4Kb FRAM Serial 3V Memory
FM25L04 ETC-FM25L04 Datasheet
187Kb / 12P
   4Kb FRAM Serial 3V Memory
FM25040 ETC-FM25040 Datasheet
631Kb / 14P
   4Kb FRAM Serial Memory
FM24CL04 ETC-FM24CL04 Datasheet
119Kb / 12P
   4Kb FRAM Serial Memory
logo
Ramtron International C...
FM24CL04 RAMTRON-FM24CL04_05 Datasheet
116Kb / 11P
   4Kb FRAM Serial Memory
FM25040A RAMTRON-FM25040A Datasheet
141Kb / 13P
   4Kb FRAM Serial Memory
logo
List of Unclassifed Man...
FM24C04A ETC1-FM24C04A Datasheet
100Kb / 12P
   4Kb FRAM Serial Memory
logo
Ramtron International C...
FM24C04A RAMTRON-FM24C04A_05 Datasheet
98Kb / 12P
   4Kb FRAM Serial Memory
FM25L512 RAMTRON-FM25L512 Datasheet
163Kb / 13P
   512Kb FRAM Serial 3V Memory
FM25L16 RAMTRON-FM25L16_06 Datasheet
146Kb / 14P
   16Kb FRAM Serial 3V Memory
More results


Html Pages

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


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : 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  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com