GD32F20x User Manual
727
This register has to be accessed by word(32-bit)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
ASYNCMOD[1:0]
DLAT[3:0]
CKDIV[3:0]
BUSLAT[3:0]
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DSET[7:0]
AHLD[3:0]
ASET[3:0]
rw
rw
rw
Bits
Fields
Descriptions
31:30
Reserved
Must be kept at reset value.
29:28
ASYNCMOD[1:0]
Asynchronous access mode
The bits are valid only when the EXMEN bit in the EXMC_SNCTLx register is 1.
00: Mode A access
01: Mode B access
10: Mode C access
11: Mode D access
27:24
DLAT[3:0]
Data latency for NOR Flash. Only valid in synchronous access
0x0: Data latency of first burst access is 2 CLK
0x1: Data latency of first burst access is 3 CLK
……
0xF: Data latency of first burst access is 17 CLK
23:20
CKDIV[3:0]
Synchronous clock divide ratio. This filed is only effect in synchronous mode.
0x0: Reserved
0x1: EXMC_CLK period = 2 * HCLK period
……
0xF: EXMC_CLK period = 16 * HCLK period
19:16
BUSLAT[3:0]
Bus latency
The bits are defined in multiplexed read mode in order to avoid bus contention,
and represent the data bus to return to a high impedance state's minimum.
0x0: Bus latency = 1* HCLK period
0x1: Bus latency = 2 * HCLK period
……
0xF: Bus latency = 16 * HCLK period
15:8
DSET[7:0]
Data setup time
This field is meaningful only in asynchronous access.
0x00: Reserved
0x01: Data setup time = 2 * HCLK period
……
0xFF: Data setup time = 256 * HCLK period
7:4
AHLD[3:0]
Address hold time
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...