GD32F20x User Manual
732
NAND flash/PC card common space timing configuration registers
(EXMC_NPCTCFGx) (x=1, 2, 3)
Address offset: 0x48 + 0x20 * x, (x = 1, 2, and 3)
Reset value: 0xFFFF FFFF
These operations applicable to common memory space for 16-bit PC Card, CF card and
NAND Flash.
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
COMHIZ[7:0]
COMHLD[7:0]
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
COMWAIT[7:0]
COMSET[7:0]
rw
rw
Bits
Fields
Description
31:24
COMHIZ[7:0]
Common memory data bus HiZ time
The bits are defined as time of bus keep high impedance state after writing the
data.
0x00: COMHIZ = 1 * HCLK
……
0xFE: COMHIZ = 255 * HCLK
0xFF: COMHIZ = 256 * HCLK
23:16
COMHLD[7:0]
Common memory hold time
After sending the address, the bits are defined as the address hold time. In write
operation, they are also defined as the data signal hold time.
0x00: Reserved
0x01: COMHLD = 1 * HCLK
……
0xFE: COMHLD = 254 * HCLK
0xFF: COMHLD = 255 * HCLK
15:8
COMWAIT[7:0]
Common memory wait time
Define the minimum time to maintain command
0x00: Reserved
0x01: COMWAIT = 2 * HCLK (+NWAIT active cycles)
……
0xFE: COMWAIT = 255 * HCLK (+NWAIT active cycles)
0xFF: COMWAIT = 256 * HCLK (+NWAIT active cycles)
7:0
COMSET[7:0]
Common memory setup time
Define the time to build address before sending command
0x00: COMSET = 1 * HCLK
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 ...