DS89C420 Ultra-High-Speed Microcontroller

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EXTERNAL CLOCK CHARACTERISTICS

PARAMETER

SYMBOL

MIN

MAX

UNITS

Clock High Time

10

ns

Clock Low Time

10

ns

Clock Rise Time

5

ns

Clock Fall Time

5

ns

SERIAL PORT MODE 0 TIMING CHARACTERISTICS

33MHz

VARIABLE

PARAMETER

SYMBOL

CONDITIONS

MIN

MAX

MIN

MAX

UNITS

SM2 = 0

360

Clock Cycle Time

SM2 = 1

120

ns

SM2 = 0

200

100

Output Data Setup to

Clock Rising

SM2 = 1

40

10

ns

SM2 = 0

50

10

Output Data Hold to Clock

Rising

SM2 = 1

20

100

ns

SM2 = 0

0

0

Input Data Hold after

Clock Rising

SM2 = 1

0

0

ns

SM2 = 0

200

100

Clock Rising Edge to Input

Data Valid

SM2 = 1

40

50

ns

Note: SM2 is the serial port 0, mode bit 2. When serial port 0 is operating in mode 0 (SM0 = SM1 = 0), SM2 determines the number of crystal

clocks in a serial-port clock cycle.

*Specifications to -40°C are guaranteed by design and not production tested.