C511 datasheet(111/128 Pages) SIEMENS

111 / 128 page

Semiconductor Group

9-11

EEPROM Programming Interface

SAB-C513A-H

9.2.5 EEPROM Access Operations

Three different operations are provided for programming and verifying the EEPROM memory

contents:

Erase (delete, clear) memory content(s)

Write (program) memory content(s)

Read memory content.

All operations are byte oriented, however, for deleting and writing the memory more than one byte

can be selected (see PMSEL register description). This allows quick erasure of memory blocks or

the complete memory as well as efficient testing of the memory. Read operations only will operate

on single bytes.

9.2.5.1

Erase Operation

The erase operation clears the total EEPROM memory or a selected area of it to an initial state. In

this initial state all memory locations have a FFH as content. As in an EPROM, a program operation

can only write a “0” to a bit of an EEPROM cell, not vice versa. Therefore, before programming of

the EEPROM, the bytes to be programmed should be erased.

At the erase operation the following steps must be executed:

1. Selection of the memory area (block or single byte) to be erased by programming PMSEL.

2. Writing the address of the byte/block to be cleared into PADRH and PADRL.

3. Set EEPROM operation mode bits in PCNTRL to EOM2-0=001B and the PROG bit to 1.

4. Wait at least 10 ms.

5. Reset the PROG bit to 0 with still EOM2-0=001B.

6. Wait 20

µs (guard time for discharging high voltage generator).

7. Set EOM2-0=000B and PROG=0.

The steps of the erase operation are illustrated in figure 9-9-6.

Figure 9-6

Erase Sequence

After erasing a memory byte contains FFH.

C511 Datasheet(PDF) 111 Page - Siemens Semiconductor Group