DocID018909 Rev 11
RM0090
Flexible memory controller (FMC)
1669
WAIT management in asynchronous accesses
If the asynchronous memory asserts the WAIT signal to indicate that it is not yet ready to
accept or to provide data, the ASYNCWAIT bit has to be set in FMC_BCRx register.
Table 278. FMC_BCRx bit fields
Bit No.
Bit name
Value to set
31-21
Reserved
0x000
20
CCLKEN
As needed
19
CBURSTRW
0x0 (no effect in asynchronous mode)
18:16
CPSIZE
0x0 (no effect in asynchronous mode)
15
ASYNCWAIT
Set to 1 if the memory supports this feature. Otherwise keep at
0.
14 EXTMOD
0x0
13
WAITEN
0x0 (no effect in asynchronous mode)
12
WREN
As needed
11
WAITCFG
Don’t care
10
WRAPMOD
0x0
9
WAITPOL
Meaningful only if bit 15 is 1
8 BURSTEN
0x0
7 Reserved
0x1
6 FACCEN
0x1
5-4 MWID
As
needed
3-2
MTYP[1:0]
0x2 (NOR Flash memory)
1 MUXEN
0x1
0 MBKEN
0x1
Table 279. FMC_BTRx bit fields
Bit No.
Bit name
Value to set
31:30
Reserved
0x0
29-28
ACCMOD
0x0
27-24
DATLAT
Don’t care
23-20
CLKDIV
Don’t care
19-16
BUSTURN
Time between NEx high to NEx low (BUSTURN HCLK)
15-8
DATAST
Duration of the second access phase (DATAST HCLK cycles for
read accesses and 1 HCLK cycles for write accesses).
7-4
ADDHLD
Duration of the middle phase of the access (ADDHLD HCLK cycles).
3-0
ADDSET[3:0]
Duration of the first access phase (ADDSET HCLK cycles).
Minimum value for ADDSET is 1.