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GD32F403xx User Manual
584
Bit Position
Bit Name
Reference Setting Value
EXMC_SNCTLx
3-2
NRTP
Depends on memory
,
0x1/0x2
1
NRMUX
0x1, Depends on memory and users
0
NRBKEN
0x1
EXMC_SNTCFGx(Read)
31-30
Reserved
0x0
29-28
ASYNCMOD
0x0
27-24
DLAT
Data latency
23-20
CKDIV
The figure above
:
0x1,EXMC_CLK=2HCLK
19-16
BUSLAT
Time between EXMC_NE[x] rising edge to
EXMC_NE[x] falling edge
15-8
DSET
No effect
7-4
AHLD
No effect
3-0
ASET
No effect
Mode SM
–Synchronous mux burst write timing – PSRAM (CRAM)
Figure 21-22. Write timing of synchronous multiplexed burst mode
Address
(EXMC_A[25:16])
Address Valid
(EXMC_NADV)
Chip Enable
(EXMC_NEx)
Output Enable
(EXMC_NOE)
Write Enable
(EXMC_NWE)
HCLK
Clock
(EXMC_CLK)
Wait
(EXMC_NWAIT)
Data
(EXMC_D[15:0])
Address [15:0]
Data Latency ( 2 EXMC_CLK)
Wait Cycle (NRWTCFG = 0)
Address [25:16]
EXMC
Data 2
EXMC
Data 3
Burst write of three half-words
EXMC
Data 1
Table 21-13. Timing configurations of synchronous multiplexed write mode
Bit Position
Bit Name
Reference Setting Value
EXMC_SNCTLx
31-20
Reserved
0x000
19
SYNCWR
0x1, synchronous write enable
18-16
CPS
0x0