ST7LITE25F2 STMicroelectronics, ST7LITE25F2 Datasheet - Page 14

• Manufacturer Part Number: ST7LITE25F2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMicroelectronics

Specifications of ST7LITE25F2

• 8 Kbytes Single Voltage Flash Program Memory With Read-out Protection, In-circuit Programming And In-application Programming (icp And Iap). 10k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55˚C.
• Clock Sources: Internal 1% RC oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-Halt, Wait and Slow, Auto Wake Up From Halt

ST7LITE2
FLASH PROGRAM MEMORY (Cont’d)
4.5 Memory Protection
There are two different types of memory protec-
tion: Read Out Protection and Write/Erase Protec-
tion which can be applied individually.
4.5.1 Read-out Protection
Read-out protection, when selected provides a
protection against program memory content ex-
traction and against write access to Flash memo-
ry. Even if no protection can be considered as to-
tally unbreakable, the feature provides a very high
level of protection for a general purpose microcon-
troller. Both program and data E
tected.
In flash devices, this protection is removed by re-
programming the option. In this case, both pro-
gram and data E
erased and the device can be reprogrammed.
Read-out protection selection depends on the de-
vice type:
– In Flash devices it is enabled and removed
– In ROM devices it is enabled by mask option
4.5.2 Flash Write/Erase Protection
Write/erase protection, when set, makes it impos-
sible to both overwrite and erase program memo-
ry. It does not apply to E
provide advanced security to applications and pre-
vent any change being made to the memory con-
tent.
14/133
1
through the FMP_R bit in the option byte.
specified in the Option List.
2
memory are automatically
2
data. Its purpose is to
2
memory are pro-
Warning: Once set, Write/erase protection can
never be removed. A write-protected flash device
is no longer reprogrammable.
Write/erase protection is enabled through the
FMP_W bit in the option byte.
4.6 Related Documentation
For details on Flash programming and ICC proto-
col, refer to the ST7 Flash Programming Refer-
ence Manual and to the ST7 ICC Protocol Refer-
ence Manual
4.7 Register Description
FLASH CONTROL/STATUS REGISTER (FCSR)
Read/Write
Reset Value: 000 0000 (00h)
1st RASS Key: 0101 0110 (56h)
2nd RASS Key: 1010 1110 (AEh)
Note: This register is reserved for programming
using ICP, IAP or other programming methods. It
controls the XFlash programming and erasing op-
erations.
When an EPB or another programming tool is
used (in socket or ICP mode), the RASS keys are
sent automatically.
7
0
0
.
0
0
0
OPT
LAT
PGM
0