- 您現在的位置：買賣IC網 > PDF目錄368145 > PSD302R Field Programmable Microcontroller Peripherals(可編程邏輯,無SRAM,19個可編程I/O,通用PLD有16個輸入) PDF資料下載
參數資料
| 型號： | PSD302R |
| 英文描述： | Field Programmable Microcontroller Peripherals(可編程邏輯,無SRAM,19個可編程I/O,通用PLD有16個輸入) |
| 中文描述： | 現場可編程微控制器外圍設備（可編程邏輯，無的SRAM，19余個可編程輸入/輸出，通用PLD的有16個輸入） |
| 文件頁數： | 2/3頁 |
| 文件大?。?/td> | 46K |
| 代理商： | PSD302R |
PSD3XX – Application Note 018
1-150
Use of the
Security Bit
(cont.)
All ACR and NVM configuration bits of the PSD3XX are non-volatile, so their contents will
not be erased or corrupted during the power down mode of the device (when the PSD3XX
is deselected with CSI/A19 = High) or during power down when V
CC
is removed.
The security configuration bit is user programmable and UV erasable as well, so a secured
part can be erased competely and be reprogrammed (only if the device is in a windowed
package).
Setting the security bit will lock all the contents of the PAD, ACR global configuration bits,
and NVM port configuration bits. BY setting the security bit the device cannot be entered
into Initialization and Override mode (resets the device and enters it to a known default
configuration before activating the individual read mode for each section). Any attempt after-
wards to enter the device to DIRECT mode for uploading or programming will fail. Setting
the security bit prevents a programmer from directly accessing the various sections of the
device.
Even though the EPROM, SRAM and I/O port contents are not directly disabled by setting
the security bit, it is impossible to read them by using external equipment (except by the
microcontroller in the system where the PSD3XX designed in). This is because the external
equipment will lack information about the address mapping of the eight EPROM blocks,
SRAM and I/O ports in the memory map of the microcontroller and the unknown status of
the global and I/O port configuration bits.
Even if an unauthorized user figures out the configuration of the part by knowing what
microcontroller is interfaced (ALE polarity, what type of read and write signals, etc.) and
gets data out of the PSD3XX (after applying address and control signals to the device), the
user will nave no idea where it came from: EPROM, SRAM, I/O Port Register, Page
Register, etc. This effectively renders the data useless.
The security configuration bit is called CSECURITY.
If CSECURITY = 0, it means security is off (security bit is not set and its value will be ‘1’ in
the object file).
If CSECURITY = 1, it means security is on (security bit is set and its value will be ‘0’ in the
object file).
Setting the security bit and activating the security mode can be done in two different ways:
1) By turning security ON in the configuration menu of Maple development software.
2) Be setting the security in the programming software (done after the device is fully
programmed and verified).
Using Maple development software to turn security ON gives the security bit the value ‘0’,
and will integrate it in one of the ACR addresses of the object file created after compilation.
(See Security Bit File Location section of this document).
If Setting of the security bit is done in the programming software (Third party programming
software or WSI Mappro programming software), the user should program and verify the
device using a Maple generated object file (with security option OFF) and then set the
security ON by using a separate programming software command.
Some third party programmer manufacturer’s software will load the Maple generated object
file but mask the security bit before programming the device. In that case the user will
have to set the security bit (if necessary) by using a separate command in the programming
software menu.
Setting the
Security Bit
相關PDF資料 |
PDF描述 |
|---|---|
| PSD303L | Field Programmable Microcontroller Peripherals(可編程邏輯,16K位SRAM,19個可編程I/O,通用PLD有16個輸入) |
| PSD303 | Field Programmable Microcontroller Peripherals(可編程邏輯,16K位SRAM,19個可編程I/O,通用PLD有16個輸入) |
| PSD311L | Field Programmable Microcontroller Peripherals(可編程邏輯,16K位SRAM,19個可編程I/O,通用PLD有12個輸入) |
| PSD311 | Field Programmable Microcontroller Peripherals(可編程邏輯,16K位SRAM,19個可編程I/O,通用PLD有12個輸入) |
| PSD312-15IB | Field-Programmable Peripheral |
相關代理商/技術參數 |
參數描述 |
|---|---|
| PSD302R-12J | 制造商:WSI 功能描述: |
| PSD302R-15J | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Field Programmable Microcontroller Peripherals |
| PSD302R-15JI | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Field Programmable Microcontroller Peripherals |
| PSD302R-15JM | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Field Programmable Microcontroller Peripherals |
| PSD302R-20J | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Low Cost Field Programmable Microcontroller Peripherals |
發(fā)布緊急采購，3分鐘左右您將得到回復。