AT45DB021D_08 datasheet(35/52 Pages) ATMEL

35 / 52 page

3638F–DFLASH–4/08

AT45DB021D

19. Input Test Waveforms and Measurement Levels

tR, tF < 2 ns (10% to 90%)

20. Output Test Load

21. AC Waveforms

Six different timing waveforms are shown on page 36. 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 66 MHz. 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 (max-

imum frequency = 66 MHz) of the RapidS serial case.

DRIVING

LEVELS

MEASUREMENT

LEVEL

0.45V

1.5V

2.4V

DEVICE

UNDER

TEST

30 pF

AT45DB021D 데이터시트(PDF) 35 Page - ATMEL Corporation