ST72344K2 datasheet(32/247 Pages) STMICROELECTRONICS

32 / 247 page

Data EEPROM

ST72344xx, ST2345xx

32/247

Doc ID 12321 Rev 6

Read operation (E2LAT = 0)

The EEPROM can be read as a normal ROM location when the E2LAT bit of the EECSR

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 E2PGM 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.

The programming cycle is fully completed when the E2PGM bit is cleared.

Note:

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 results)

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 the Figure 10.

Figure 8.

Data EEPROM programming flowchart

READ MODE

E2LAT = 0

E2PGM = 0

WRITE MODE

E2LAT = 1

E2PGM = 0

READ BYTES

IN EEPROM AREA

WRITE UP TO 32 BYTES

IN EEPROM AREA

(with the same 11 MSB of the address)

START PROGRAMMING CYCLE

E2LAT=1

E2PGM=1 (set by software)

E2PGM

CLEARED BY HARDWARE

ST72344K2 датащи(PDF) 32 Page - STMicroelectronics

ST72344K2 датащи(HTML) 32 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL