전자부품 데이터시트 검색엔진 |
|
AM49DL6408H55FT 데이터시트(PDF) 21 Page - SPANSION |
|
AM49DL6408H55FT 데이터시트(HTML) 21 Page - SPANSION |
21 / 57 page March 12, 2004 Am49DL6408H 19 ADV ANCE I N FO RMAT I O N Figure 3. SecSi Sector Protect Verify Hardware Data Protection The command sequence requirement of unlock cycles for programming or erasing provides data protection against inadvertent writes (refer to Table 11 for com- mand definitions). In addition, the following hardware data protection measures prevent accidental erasure or programming, which might otherwise be caused by spurious system level signals during V CC power-up and power-down transitions, or from system noise. Low VCC Write Inhibit When V CC is less than VLKO, the device does not ac- cept any write cycles. This protects data during V CC power-up and power-down. The command register and all internal program/erase circuits are disabled, and the device resets to the read mode. Subsequent writes are ignored until V CC is greater than VLKO. The system must provide the proper signals to the control pins to prevent unintentional writes when V CC is greater than V LKO. Write Pulse “Glitch” Protection Noise pulses of less than 5 ns (typical) on OE#, CE#f or WE# do not initiate a write cycle. Logical Inhibit Write cycles are inhibited by holding any one of OE# = V IL, CE#f = VIH or WE# = VIH. To initiate a write cycle, CE#f and WE# must be a logical zero while OE# is a logical one. Power-Up Write Inhibit If WE# = CE#f = V IL and OE# = VIH during power up, the device does not accept commands on the rising edge of WE#. The internal state machine is automati- cally reset to the read mode on power-up. COMMON FLASH MEMORY INTERFACE (CFI) The Common Flash Interface (CFI) specification out- lines device and host system software interrogation handshake, which allows specific vendor-specified software algorithms to be used for entire families of devices. Software support can then be device-inde- pendent, JEDEC ID-independent, and forward- and backward-compatible for the specified flash device families. Flash vendors can standardize their existing interfaces for long-term compatibility. This device enters the CFI Query mode when the sys- tem writes the CFI Query command, 98h, to address 55h in word mode (or address AAh in byte mode), any time the device is ready to read array data. The system can read CFI information at the addresses given in Tables 7–10. To terminate reading CFI data, the system must write the reset command.The CFI Query mode is not accessible when the device is exe- cuting an Embedded Program or embedded Erase al- gorithm. The system can also write the CFI query command when the device is in the autoselect mode. The device enters the CFI query mode, and the system can read CFI data at the addresses given in Tables 7–10. The system must write the reset command to return the de- vice to reading array data. For further information, please refer to the CFI Specifi- cation and CFI Publication 100, available via the World Wide Web at http://www.amd.com/flash/cfi. Al- ternatively, contact an AMD representative for copies of these documents. Write 60h to any address Write 40h to SecSi Sector address with A6 = 0, A1 = 1, A0 = 0 START RESET# = VIH or VID Wait 1 µs Read from SecSi Sector address with A6 = 0, A1 = 1, A0 = 0 If data = 00h, SecSi Sector is unprotected. If data = 01h, SecSi Sector is protected. Remove VIH or VID from RESET# Write reset command SecSi Sector Protect Verify complete |
유사한 부품 번호 - AM49DL6408H55FT |
|
유사한 설명 - AM49DL6408H55FT |
|
|
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 |