Rainbow Electronics AT45DB161D - Manual (Page 32)

32
3500O–DFLASH–11/2012
AT45DB161D
19. Input Test Waveforms and Measurement Levels
t
R
, t
F
< 2ns (10% to 90%)
20. Output Test Load
21. AC Waveforms
Six different timing waveforms are shown on page 32 . Waveform 1 shows the SCK signal being low when CS
makes a high-to-low transition, and waveform 2 shows the SCK signal being high when CS makes a high-to-low
transition. In both cases, output SO becomes valid while the SCK signal is still low (SCK low time is specified as
t
WL
). Timing waveforms 1 and 2 conform to RapidS serial interface but for frequencies up to 66MHz. Waveforms 1
and 2 are compatible with SPI Mode 0 and SPI Mode 3, respectively.
Waveform 3 and waveform 4 illustrate general timing diagram for RapidS serial interface. These are similar to
waveform 1 and waveform 2, except that output SO is not restricted to become valid during the t
WL
period. These
timing waveforms are valid over the full frequency range (maximum frequency = 66MHz) of the RapidS serial case.
21.1 Waveform 1 – SPI Mode 0 Compatible (for frequencies up to 66MHz)
AC
DRIVING
LEVELS
AC
MEASUREMENT
LEVEL
0.45V
1.5V
2.4V
DEVICE
UNDER
TEST
30pF
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