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GD32F403xx User Manual
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Figure 21-9. Mode A write access
Address
(EXMC_A[25:0])
Byte Lane Select
(EXMC_NBL[1:0])
Chip Enable
(EXMC_NEx)
Output Enable
(EXMC_NOE)
Write Enable
(EXMC_NWE)
Data
(EXMC_D[15:0])
Address Setup Time
(WASET+1 HCLK)
Data Setup Time
(WDSET HCLK)
EXMC Output
1 HCLK
The different between mode A and mode 1 write timing is that read/write timing is specified
by the same set of timing configuration, while mode A write timing configuration is
independent of its read configuration.
Table 21-7. Mode A related registers configuration
Bit Position
Bit Name
Reference Setting Value
EXMC_SNCTLx
31-20
Reserved
0x000
19
SYNCWR
0x0
18-16
CPS
0x0
15
ASYNCWTEN
Depends on memory
14
EXMODEN
0x1
13
NRWTEN
0x0
12
WEN
Depends on user
11
NRWTCFG
No effect
10
WRAPEN
0x0
9
NRWTPOL
Meaningful only when the bit 15 is set to 1
8
SBRSTEN
0x0
7
Reserved
0x1
6
NREN
No effect
5-4
NRW
Depends on memory
3-2
NRTP
Depends on memory, except 2(Nor Flash)
1
NRMUX
0x0
0
NRBKEN
0x1
EXMC_SNTCFGx(Read)
31-30
Reserved
0x0
29-28
ASYNCMOD
0x0
27-24
DLAT
No effect
23-20
CKDIV
No effect