DocID018909 Rev 11
RM0090
Flexible memory controller (FMC)
1669
37.7.5 SDRAM
controller
registers
SDRAM Control registers 1,2 (FMC_SDCR1,2)
Address offset: 0x140+ 4* (x – 1), x = 1,2
Reset value: 0x0000 02D0
This register contains the control parameters for each SDRAM memory bank
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Reserved
RP
IP
E
[1
:0
]
R
B
URST
.
SDCLK
[1:
0]
WP
C
A
S[
1:
0]
NB
M
W
ID
[1
:0
]
NR[1
:0]
NC[1
:0]
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:15 Reserved, must be kept at reset value
Bits 14:13
RPIPE[1:0]:
Read pipe
These bits define the delay, in HCLK clock cycles, for reading data after CAS latency.
00: No HCLK clock cycle delay
01: One HCLK clock cycle delay
10: Two HCLK clock cycle delay
11: reserved, do not use
Note: The corresponding bits in the FMC_SDCR2 register are read only.
Bit 12
RBURST:
Burst read
This bit enables burst read mode. The SDRAM controller anticipates the next read commands
during the CAS latency and stores data in the Read FIFO.
0: single read requests are not managed as bursts
1: single read requests are always managed as bursts
Note: The corresponding bit in the FMC_SDCR2 register is don’t care.
Bits 11:10
S
DCLK[1:0]:
SDRAM clock configuration
These bits define the SDRAM clock period for both SDRAM banks and allow disabling the clock
before changing the frequency. In this case the SDRAM must be re-initialized.
00: SDCLK clock disabled
01: Reserved
10: SDCLK period = 2 x HCLK periods
11: SDCLK period = 3 x HCLK periods
Note: The corresponding bits in the FMC_SDCR2 register are read only.
Bit 9
WP:
Write protection
This bit enables write mode access to the SDRAM bank.
0: Write accesses allowed
1: Write accesses ignored
Bits 8:7
CA
S
[1:0]:
CAS Latency
This bits sets the SDRAM CAS latency in number of memory clock cycles
00: reserved, do not use.
01: 1 cycle
10: 2 cycles
11: 3 cycles