ST7DALIF2 STMicroelectronics, ST7DALIF2 Datasheet - Page 24

• Manufacturer Part Number: ST7DALIF2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI
• Manufacturer: STMicroelectronics

Specifications of ST7DALIF2

• 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.
• 256 Bytes Data Eeprom With Read-out Protection. 300k 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

Data EEPROM
Note:
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On this device, Data EEPROM can also be used to execute machine code. Take care not to
write to the Data EEPROM while executing from it. This would result in an unexpected code
being executed.
Write operation (E2LAT=1)
To access the write mode, the E2LAT bit has to be set by software (the E2PGM bit remains
cleared). When a write access to the EEPROM area occurs, the value is latched inside the
32 data latches according to its address.
When PGM bit is set by the software, all the previous bytes written in the data latches (up to
32) are programmed in the EEPROM cells. The effective high address (row) is determined
by the last EEPROM write sequence. To avoid wrong programming, the user must take care
that all the bytes written between two programming sequences have the same high address:
only the five Least Significant Bits of the address can change.
At the end of the programming cycle, the PGM and LAT bits are cleared simultaneously.
Care should be taken during the programming cycle. Writing to the same memory location
will over-program the memory (logical AND between the two write access data result)
because the data latches are only cleared at the end of the programming cycle and by the
falling edge of the E2LAT bit.
It is not possible to read the latched data.
This note is illustrated by
Figure 6.
Data EEPROM programming flowchart
IN EEPROM AREA
READ MODE
READ BYTES
CLEARED BY HARDWARE
E2PGM=0
E2LAT=0
Figure
8.
(with the same 11 MSB of the address)
START PROGRAMMING CYCLE
E2PGM=1 (set by software)
WRITE UP TO 32 BYTES
0
IN EEPROM AREA
WRITE MODE
E2PGM=0
E2LAT=1
E2LAT=1
E2LAT
1
ST7DALIF2