Datasheet

Data EEPROM ST7LITE20F2 ST7LITE25F2 ST7LITE29F2

28/170 DocID8349 Rev 7

5.6 Data EEPROM Read-out protection

The Read-out protection is enabled through an option bit (see Section 15.1: Option bytes).

When this option is selected, the programs and data stored in the EEPROM memory are

protected against Read-out (including a re-write protection). In Flash devices, when this

protection is removed by reprogramming the Option Byte, the entire Program memory and

EEPROM is first automatically erased.

Note: Both Program Memory and DATA EEPROM are protected using the same option bit.

Figure 9. Data EEPROM programming cycle

5.7 Register description

EEPROM Control/Status register (EECSR)

Read / Write

Reset Value: 0000 0000 (00h)

• Bits 7:2 = Reserved, forced by hardware to 0.

• Bit 1 = E2LAT Latch Access Transfer

This bit is set by software. It is cleared by hardware at the end of the programming

cycle. It can only be cleared by software if the E2PGM bit is cleared.

0: Read mode

1: Write mode

• Bit 0 = E2PGM Programming control and status

This bit is set by software to begin the programming cycle. At the end of the

programming cycle, this bit is cleared by hardware.

0: Programming finished or not yet started

1: Programming cycle is in progress

Note: If the E2PGM bit is cleared during the programming cycle, the memory data is not

guaranteed.

LAT

Erase cycle Write cycle

PGM

PROG

Read operation not possible

Write of

data latches

Read operation possible

Internal

programming

voltage

7 0

000000E2LATE2PGM