 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
FM25V10-GTR Datasheet(PDF) 5 Page - Ramtron International Corporation |
|
||||||||||||||||||||||||||||||
FM25V10-GTR Datasheet(HTML) 5 Page - Ramtron International Corporation |
|
|
5 / 16 page  FM25V10 - 1Mb SPI FRAM Rev. 2.0 May 2010 Page 5 of 16 Power Up to First Access The FM25V10 is not accessible for a period of time (tPU) after power up. Users must comply with the timing parameter tPU, which is the minimum time from VDD (min) to the first /S low. Data Transfer All data transfers to and from the FM25V10 occur in 8-bit groups. They are synchronized to the clock signal (C), and they transfer most significant bit (MSB) first. Serial inputs are registered on the rising edge of C. Outputs are driven from the falling edge of clock C. Command Structure There are ten commands called op-codes that can be issued by the bus master to the FM25V10. 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 operations. They perform a single function, such as to enable a write operation. Second are commands followed by one byte, either in or out. They operate on the Status Register. The third group includes 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 0011b FSTRD Fast Read Memory Data 0000 1011b WRITE Write Memory Data 0000 0010b SLEEP Enter Sleep Mode 1011 1001b RDID Read Device ID 1001 1111b SNR Read S/N 1100 0011b WREN – Set Write Enable Latch The FM25V10 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 (WRSR) and writing the memory (WRITE). 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. Attempting to write the WEL bit in the Status Register has no effect on the state of this 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. 0 0 0 0 0 1 1 0 S C D Q Hi-Z 0 1 2 3 4 5 6 7 Figure 5. WREN 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. 0 0 0 0 0 1 0 0 S C D Q Hi-Z 0 1 2 3 4 5 6 7 Figure 6. WRDI Bus Configuration RDSR – Read Status Register The RDSR command allows the bus master to verify the contents of the Status Register. Reading Status provides information about the current state of the write protection features. Following the RDSR op-code, the FM25V10 will return one byte with the contents of the Status Register. The Status Register is described in detail in the section below. |
Similar Part No. - FM25V10-GTR |
|
Similar Description - FM25V10-GTR |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
