
GD32F403xx User Manual
575
Bit Position
Bit Name
Reference Setting Value
6
NREN
0x1
5-4
NRW
Depends on memory
3-2
NRTP
0x2
,
NOR Flash
1
NRMUX
0x0
0
NRBKEN
0x1
EXMC_SNTCFGx(Read and write in mode 2,read in mode B)
31-30
Reserved
0x0000
29-28
ASYNCMOD
Mode B:0x1
27-24
DLAT
No effect
23-20
CKDIV
No effect
19-16
BUSLAT
Time between EXMC_NE[x] rising edge to
EXMC_NE[x] falling edge
15-8
DSET
Depends on memory and user (DSET+3 HCLK for
read)
7-4
AHLD
0x0
3-0
ASET
Depends on memory and user
EXMC_SNWTCFGx(Write in mode B)
31-30
Reserved
0x0000
29-28
WASYNCMOD
Mode B:0x1
27-20
Reserved
0x00
19-16
WBUSLAT
Time between EXMC_NE[x] rising edge to
EXMC_NE[x] falling edge
15-8
WDSET
Depends on memory and user (WDSET+1 HCLK
for write)
7-4
WAHLD
0x0
3-0
WASET
Depends on memory and user
Mode C - NOR Flash OE toggling
Figure 21-13. Mode C read access
Address
(EXMC_A[25:0])
Address Valid
(EXMC_NADV)
Chip Enable
(EXMC_NEx)
Output Enable
(EXMC_NOE)
Write Enable
(EXMC_NWE)
Data
(EXMC_D[15:0])
Memory Output
Address Setup Time
(ASET+1 HCLK)
Data Setup Time
(DSET+1 HCLK)
2 HCLK