전자부품 데이터시트 검색엔진 |
|
SST39VF800Q-90-4C-EK 데이터시트(PDF) 2 Page - Silicon Storage Technology, Inc |
|
SST39VF800Q-90-4C-EK 데이터시트(HTML) 2 Page - Silicon Storage Technology, Inc |
2 / 23 page 2 © 1999 Silicon Storage Technology, Inc. 343-04 2/99 8 Megabit Multi-Purpose Flash SST39VF800Q / SST39VF800 Advance Information The SST39VF800Q/VF800 also have the Auto Low Power mode which puts the device in a near standby mode after data has been accessed with a valid read operation. This reduces the IDD active read current from typically 15 mA to typically 3 µA. The Auto Low Power mode reduces the typical IDD active read current to the range of 1 mA/MHz of read cycle time. The device exits the Auto Low Power mode with any address transition or control signal transi- tion used to initiate another read cycle, with no access time penalty. Read The Read operation of the SST39VF800Q/VF800 is con- trolled by CE# and OE#, both have to be low for the system to obtain data from the outputs. CE# is used for device selection. When CE# is high, the chip is deselected and only standby power is consumed. OE# is the output control and is used to gate data from the output pins. The data bus is in high impedance state when either CE# or OE# is high. Refer to the Read cycle timing diagram for further details (Figure 3). Word Program Operation The SST39VF800Q/VF800 are programmed on a word- by-word basis. The Program operation consists of three steps. The first step is the three-byte load sequence for Software Data Protection. The second step is to load word address and word data. During the Word Program opera- tion, the addresses are latched on the falling edge of either CE# or WE#, whichever occurs last. The data is latched on the rising edge of either CE# or WE#, whichever occurs first. The third step is the internal Program operation which is initiated after the rising edge of the fourth WE# or CE#, whichever occurs first. The Program operation, once initi- ated, will be completed within 20 µs. See Figures 4 and 5 for WE# and CE# controlled Program operation timing diagrams and Figure 16 for flowcharts. During the Pro- gram operation, the only valid reads are Data# Polling and Toggle Bit. During the internal Program operation, the host is free to perform additional tasks. Any commands issued during the internal Program operation are ignored. Sector/Block Erase Operation The Sector/Block Erase operation allows the system to erase the device on a sector-by-sector (or block-by-block) basis. The SST39VF800Q/VF800 offer both small Sector Erase and Block Erase mode. The sector architecture is based on uniform sector size of 2 KWord. The Block Erase mode is based on uniform block size of 32 KWord. The Sector Erase operation is initiated by executing a six-byte- command sequence with Sector Erase command (30H) and sector address (SA) in the last bus cycle. The address lines A11-A18 are used to determine the sector address. The Block Erase operation is initiated by executing a six- byte command sequence with Block Erase command (50H) and block address (BA) in the last bus cycle. The address lines A15-A18 are used to determine the block address. The sector or block address is latched on the falling edge of the sixth WE# pulse, while the command (30H or 50H) is latched on the rising edge of the sixth WE# pulse. The internal Erase operation begins after the sixth WE# pulse. The end of Erase operation can be determined using either Data# Polling or Toggle Bit methods. See Figures 9 and 10 for timing waveforms. Any commands issued during the Sector or Block Erase operation are ignored. Chip Erase Operation The SST39VF800Q/VF800 provide a Chip Erase opera- tion, which allows the user to erase the entire memory array to the “1” state. This is useful when the entire device must be quickly erased. The Chip Erase operation is initiated by executing a six- byte command sequence with Chip Erase command (10H) at address 5555H in the last byte sequence. The Erase operation begins with the rising edge of the sixth WE# or CE#, whichever occurs first. During the Erase operation, the only valid read is Toggle Bit or Data# Polling. See Table 4 for the command sequence, Figure 8 for timing diagram, and Figure 19 for the flowchart. Any commands issued during the Chip Erase operation are ignored. Write Operation Status Detection The SST39VF800Q/VF800 provide two software means to detect the completion of a write (Program or Erase) cycle, in order to optimize the system write cycle time. The software detection includes two status bits: Data# Polling (DQ7) and Toggle Bit (DQ6). The end of write detection mode is enabled after the rising edge of WE#, which initiates the internal program or erase operation. The actual completion of the nonvolatile write is asynchro- nous with the system; therefore, either a Data# Polling or Toggle Bit read may be simultaneous with the completion of the write cycle. If this occurs, the system may possibly get an erroneous result, i.e., valid data may appear to conflict with either DQ7or DQ6. In order to prevent spurious rejection, if an erroneous result occurs, the software rou- tine should include a loop to read the accessed location an additional two (2) times. If both reads are valid, then the device has completed the write cycle, otherwise the rejec- tion is valid. Data# Polling (DQ7) When the SST39VF800Q/VF800 are in the internal Pro- gram operation, any attempt to read DQ7 will produce the complement of the true data. Once the Program operation is completed, DQ7 will produce true data. The device is |
유사한 부품 번호 - SST39VF800Q-90-4C-EK |
|
유사한 설명 - SST39VF800Q-90-4C-EK |
|
|
링크 URL |
개인정보취급방침 |
ALLDATASHEET.CO.KR |
ALLDATASHEET 가 귀하에 도움이 되셨나요? [ DONATE ] |
Alldatasheet는? | 광고문의 | 운영자에게 연락하기 | 개인정보취급방침 | 링크교환 | 제조사별 검색 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 |