Samsung S3F401F - Manual (Page 63)

S3F401F_UM_REV1.00 INTERNAL FLASH ROM
5-3
4. PROGRAMMING MODES
The Flash Memory Controller supports two kinds of program mode:
♦ User program mode
♦ Tool program mode
4.1 USER PROGRAM MODE
The user program mode for flash memory programming and sector erasing uses the internal high voltage generator,
which is necessary for flash memory programming and sector erasing. In other words, the Flash Memory Controller
has an internal high voltage pumping circuit. Therefore, high voltage to V
PP pin is not needed. To program the data
into the flash ROM or sector erase in this mode, several control registers should be used, which will be explained
below.
4.1.1 The Program Procedure in the User Program Mode
In order to program to flash memory, you should write the address to be written into the address register (FMADDR)
and the data into the data register (FMDATA), respectively. As a next step, you should write the value 0x5A5A5A5A
into the FMKEY register. Before command bit set and start, you must enable flash counter clock
(FMUCON.7-UOSCEN bit Set). Finally, by writing the appropriate data into flash memory control register
(FMUCON). After the completion of the write operation, all registers except FMUCON.8bit (INTERLEAVE) will be
cleared. To perform the next writing operation, all register should be written again as before.
In order to perform sector erase procedure is the same as program procedure except not setting the data register
(FMDATA) in Flash Memory Controller.
In order to perform chip erase procedure will be enough to setting the key register (FMKEY) and control register
(FMUCON) in Flash Memory Controller.