Samsung S3F401F - Manual (Page 62)

INTERNAL FLASH ROM S3F401F_UM_REV1.00
5-2
3. FLASH CONFIGURATION
3.1 FLASH ROM CONFIGURATION
The 256KBytes Flash ROM consists of 256 sectors. Each sector consists of 1024bytes. So, the total size of flash
ROM is 256(sector number) x 1024(each sector size) bytes (256Kbyte). You can erase the flash memory a
sector-unit at a time and write the data into the flash memory a word-unit at a time.
3.2 ADDRESS ALIGNMENT
To set an address value in FMADDR register, abide by the following rules.
♦ Sector Erase
When erasing a sector, the lower 10-bits of address should be ‘0’, because the size of a sector is 1024Bytes.
You can select one as the SECTOR_ORDER from 0 to 255, among 256 sectors.
− FMADDR [31:0] = (SECTOR_ ORDER << 10)
♦ Program
When programming Flash ROM, the lower 2-bits should be ‘0’, because data should be written to the Flash
ROM by a word-unit (4bytes). You can select one as the ADDRESS from 0x0000 to 0x3FFFF, in 256Kbytes
range. In the tool program mode, the low 2-bit address also should be 00b.
− FMADDR [31:0] = ADDRESS & 0xFFFFFFFC
3.3 WORKING MODE
There are two-different working modes following:
♦ NON-INTERLEAVE MODE
The flash memories are able to work at the system clock frequency (MCLK). In this case, all read accesses are
executed with no wait state.
♦ INTERLEAVE MODE
The flash memories work at the system clock frequency (MCLK) divided by 2. In this case, non-sequential read
accesses require one wait state and sequential read accesses are executed with no wait state. Thanks to a
cache buffer, fetch accesses at consecutive address are performed with no wait state.
3.4 PROGRAM MODE
For writing the data in flash ROM, you can access the flash ROM by a program or the external serial interface.
Because of the feature of NOR flash memory, you can program the data in any address and in any time. The size of
embedded flash memory in S3F401F is 256K-byte and it has the following features:
♦ User program mode (AHB Interface)
♦ Tool program mode (Use the dedicated serial interface)
♦ Protection mode: hardware protection and read protection
The S3F401F has several pins used for flash ROM writer to read/write/erase the flash memory (VDDIO[3:0],
VSSIO[3:0], nRESET, VDDCORE[3:0], VSSCORE[3:0], SDAT, SCLK), which is the programming by tool program
mode. These several pins are multiplexed with other functional pins.