ST STM32F405 User Manual

RM0090 Rev 18 1675/1749
RM0090 Flexible memory controller (FMC)
1682
Note: Before modifying the RBURST or RPIPE settings or disabling the SDCLK clock, the user
must first send a PALL command to make sure ongoing operations are complete.
SDRAM Timing registers 1,2 (FMC_SDTR1,2)
Address offset: 0x148 + 4 * (x – 1), x = 1,2
Reset value: 0x0FFF FFFF
This register contains the timing parameters of each SDRAM bank
Bit 6 NB: Number of internal banks
This bit sets the number of internal banks.
0: Two internal Banks
1: Four internal Banks
Bits 5:4 MWID[1:0]: Memory data bus width.
These bits define the memory device width.
00: 8 bits
01: 16 bits
10: 32 bits
11: reserved, do not use.
Bits 3:2 NR[1:0]: Number of row address bits
These bits define the number of bits of a row address.
00: 11 bit
01: 12 bits
10: 13 bits
11: reserved, do not use.
Bits 1:0 NC[1:0]: Number of column address bits
These bits define the number of bits of a column address.
00: 8 bits
01: 9 bits
10: 10 bits
11: 11 bits.
313029282726252423222120191817161514131211109876543210
Reserved TRCD[3:0] TRP[3:0 TWR[3:0 TRC[3:0 TRAS[3:0 TXSR[3:0 TMRD[3:0
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:28 Reserved, must be kept at reset value
Bits 27:24 TRCD[3:0]: Row to column delay
These bits define the delay between the Activate command and a Read/Write command in number of
memory clock cycles.
0000: 1 cycle.
0001: 2 cycles
....
1111: 16 cycles

ST STM32F405 Specifications

General

Brand	ST
Model	STM32F405
Category	Computer Hardware
Language	English