GD32W51x User Manual
725
Signal line m odes
Single m ode
Dual m ode
Quad m ode
Pins
IO0 (SO)
Output
Input:data
read
(high
impedance)
output: all other phases
Input
:
data
read (high
impedance)
Output: all other phases.
IO1 (SI)
Input (high inpedance)
IO2
Output 0 (deactivate “w rite protect function”)
IO3
Output 1 (deactivate “hold” function)
Description
In dummy phase w hen
DATAMOD = 2’b01, IO0
output, IO1 input (high
inpedance)
In dummy phase w hen
DATAMOD = 2’b10,
IO0/IO1 are alw ays high-
impedance.
In dummy phase w hen
DATAMOD = 2’b11,
IO0/IO1/IO2/IO3 are
alw ays high-impedance.
IO2/IO3 are used only in quad mode, if none of the 5 phases are configured in quad mode,
then IO2/IO3 are released and can be used for other functions even when QSPI is enabled.
22.3.4.
CSN and SCK behavior
The default value of CSN is high, and it falls before a command begins and rises as soon as
it finishes.
SCK output signal is a gate signal from internal sck, where the internal sck is present all the
time.
CSN falls one SCK cycle before the first valid rising SCK edge, and rises on SCK cycle after
the final valid rising SCK edge.