GD32W51x User Manual
712
SQPI_CSN
Output
Chip-Enable (active low )
Com m and Phase
SQPI_D0
Output
O
O
O
O
O
O
SQPI_D1
Output
X
X
X
O
X
X
SQPI_D2
Output
0
0
0
O
0
0
SQPI_D3
Output
1
1
1
O
1
1
Address Phase
SQPI_D0
Output
O
O
O
O
O
O
SQPI_D1
Output
X
X
O
O
X
O
SQPI_D2
Output
0
0
O
O
0
0
SQPI_D3
Output
1
1
O
O
1
1
Waitcycle Phase
SQPI_D0
Inout
X
X
X
X
X
X
SQPI_D1
Inout
X
X
X
X
X
X
SQPI_D2
Inout
0
X
X
X
0
0
SQPI_D3
Inout
1
X
X
X
1
1
Data Phase
SQPI_D0
Inout
O
IO
IO
IO
IO
IO
SQPI_D1
Inout
I
IO
IO
IO
IO
IO
SQPI_D2
Inout
X
IO
IO
IO
X
X
SQPI_D3
Inout
X
IO
IO
IO
X
X
Note: O – Output, I – Input, IO – Inout, 0 – Output 0, 1 – Output 1, X - Hiz
21.3.2.
SQPI controller sampling polarity
SQPI controller read operation sampling polarity (PL bit in SQPI_INIT register) selection
function support user to change the controller sampling time. This function is highly useful
when SQPI clock is high. Example showed as below:
Figure 21-1.
SQPI Polarity Example
SQPI_D0
SQPI_D1
SQPI_CLK
SQPI_CSN
SQPI_D2
SQPI_D3
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Command Phase
Address Phase
Data Phase
Waitcycle Phase
0
1
2
3
4
5
6
7
1
st
Sample Time
(SQPI_PL=0)
1
st
Sample Time
(SQPI_PL=1)