Rainbow Electronics AT45DB321B - Manual (Page 14)

14
AT45DB321B
2223D–DFLASH–10/02
Input Test Waveforms and Measurement Levels
t
R
, t
F
< 3 ns (10% to 90%)
Output Test Load
AC Waveforms
Two different timing diagrams are shown below. Waveform 1 shows the SCK signal
being low when CS makes a high-to-low transition, and Waveform 2 shows the SCK sig-
nal being high when CS makes a high-to-low transition. Both waveforms show valid
timing diagrams. The setup and hold times for the SI signal are referenced to the low-to-
high transition on the SCK signal.
Waveform 1 shows timing that is also compatible with SPI Mode 0, and Waveform 2
shows timing that is compatible with SPI Mode 3.
Waveform 1 – Inactive Clock Polarity Low and SPI Mode 0
Waveform 2 – Inactive Clock Polarity High and SPI Mode 3
AC
DRIVING
LEVELS
AC
MEASUREMENT
LEVEL
0.45V
2.0
0.8
2.4V
DEVICE
UNDER
TEST
30 pF
CS
SCK
SI
SO
t
CSS
VALID IN
t
H
t
SU
t
WH
t
WL
t
CSH
t
CS
t
V
HIGH IMPEDANCE
VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE
CS
SCK
SI
SO
t
CSS
VALID IN
t
H
t
SU
t
WL
t
WH
t
CSH
t
CS
t
V
HIGH Z
VALID OUT
t
HO
t
DIS
HIGH IMPEDANCE