- 您现在的位置：买卖IC网 > PDF目录270896 > S75PL127JCDBFWB2 (Spansion Inc.) Power supply woltage of 2.7 to 3.1 volt PDF资料下载
参数资料
| 型号： | S75PL127JCDBFWB2 |
| 厂商： | Spansion Inc. |
| 英文描述： | Power supply woltage of 2.7 to 3.1 volt |
| 中文描述： | 功率2月7号至三月一日伏的电源woltage |
| 文件页数： | 109/183页 |
| 文件大小： | 4247K |
| 代理商： | S75PL127JCDBFWB2 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页当前第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页第125页第126页第127页第128页第129页第130页第131页第132页第133页第134页第135页第136页第137页第138页第139页第140页第141页第142页第143页第144页第145页第146页第147页第148页第149页第150页第151页第152页第153页第154页第155页第156页第157页第158页第159页第160页第161页第162页第163页第164页第165页第166页第167页第168页第169页第170页第171页第172页第173页第174页第175页第176页第177页第178页第179页第180页第181页第182页第183页
32
S29PL127J/S29PL064J/S29PL032J for MCP
S29PL127J_064J_032J_MCP_00_A3 August 12, 2004
Preli m inary
By issuing the DYB Write command sequences, the DYBs will be set or cleared,
thus placing each sector in the protected or unprotected state. These are the so-
called Dynamic Locked or Unlocked states. They are called dynamic states be-
cause it is very easy to switch back and forth between the protected and
unprotected conditions. This allows software to easily protect sectors against in-
advertent changes yet does not prevent the easy removal of protection when
changes are needed. The DYBs maybe set or cleared as often as needed.
The PPBs allow for a more static, and difficult to change, level of protection. The
PPBs retain their state across power cycles because they are non-volatile. Indi-
vidual PPBs are set with a command but must all be cleared as a group through
a complex sequence of program and erasing commands. The PPBs are also lim-
ited to 100 erase cycles.
The PPB Lock bit adds an additional level of protection. Once all PPBs are pro-
grammed to the desired settings, the PPB Lock may be set to “1”. Setting the PPB
Lock disables all program and erase commands to the non-volatile PPBs. In ef-
fect, the PPB Lock Bit locks the PPBs into their current state. The only way to clear
the PPB Lock is to go through a power cycle. System boot code can determine if
any changes to the PPB are needed; for example, to allow new system code to
be downloaded. If no changes are needed then the boot code can set the PPB
Lock to disable any further changes to the PPBs during system operation.
The WP#/ACC write protect pin adds a final level of hardware protection to sec-
tors SA1-133, SA1-134, SA2-0 and SA2-1. When this pin is low it is not possible
to change the contents of these sectors. These sectors generally hold system
boot code. The WP#/ACC pin can prevent any changes to the boot code that could
override the choices made while setting up sector protection during system
initialization.
For customers who are concerned about malicious viruses there is another level
of security - the persistently locked state. To persistently protect a given sector
or sector group, the PPBs associated with that sector need to be set to “1”. Once
all PPBs are programmed to the desired settings, the PPB Lock should be set to
“1”. Setting the PPB Lock automatically disables all program and erase commands
to the Non-Volatile PPBs. In effect, the PPB Lock “freezes” the PPBs into their cur-
rent state. The only way to clear the PPB Lock is to go through a power cycle.
It is possible to have sectors that have been persistently locked, and sectors that
are left in the dynamic state. The sectors in the dynamic state are all unprotected.
If there is a need to protect some of them, a simple DYB Write command se-
quence is all that is necessary. The DYB write command for the dynamic sectors
switch the DYBs to signify protected and unprotected, respectively. If there is a
need to change the status of the persistently locked sectors, a few more steps
are required. First, the PPB Lock bit must be disabled by either putting the device
through a power-cycle, or hardware reset. The PPBs can then be changed to re-
flect the desired settings. Setting the PPB lock bit once again will lock the PPBs,
and the device operates normally again.
The best protection is achieved by executing the PPB lock bit set command early
in the boot code, and protect the boot code by holding WP#/ACC = VIL.
Table 8 contains all possible combinations of the DYB, PPB, and PPB lock relating
to the status of the sector.
In summary, if the PPB is set, and the PPB lock is set, the sector is protected and
the protection can not be removed until the next power cycle clears the PPB lock.
相关PDF资料 |
PDF描述 |
|---|---|
| S75PL127JCEBFWB2 | Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCDBFWB3 | Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCEBFWB3 | Power supply woltage of 2.7 to 3.1 volt |
| S29CD016G0PFAN010 | 16 Megabit (512 K x 32-Bit) CMOS 2.5 Volt-only Burst Mode, Dual Boot, Simultaneous Read/Write Flash Memory |
| S29CD016G0PFAN012 | 16 Megabit (512 K x 32-Bit) CMOS 2.5 Volt-only Burst Mode, Dual Boot, Simultaneous Read/Write Flash Memory |
相关代理商/技术参数 |
参数描述 |
|---|---|
| S75PL127JCDBFWB3 | 制造商:SPANSION 制造商全称:SPANSION 功能描述:Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCDBFWU0 | 制造商:SPANSION 制造商全称:SPANSION 功能描述:Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCDBFWU2 | 制造商:SPANSION 制造商全称:SPANSION 功能描述:Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCDBFWU3 | 制造商:SPANSION 制造商全称:SPANSION 功能描述:Power supply woltage of 2.7 to 3.1 volt |
| S75PL127JCE | 制造商:SPANSION 制造商全称:SPANSION 功能描述:Power supply woltage of 2.7 to 3.1 volt |
发布紧急采购，3分钟左右您将得到回复。