Maxim-integrated DS80C390 Bedienungsanleitung PDF herunterladen (Seite 55)

DS80C390

55 of 58 110199

EXPLANATION OF AC SYMBOLS

This microcontroller uses timing parameters and symbols similar to the original 8051 family. The

following list of timing symbols is provided as an aid to understanding the timing diagrams.

t Time P

PSEN

A Address Q Output data

C Clock R

RD signal

CE Chip Enable V Valid

D Input data W

WR signal

H Logic level high X No longer a valid logic level

L Logic level low Z Tristate

I Instruction

POWER CYCLE TIMING CHARACTERISTICS

PARAMETER SYMBOL TYP MAX UNITS NOTE

Crystal start-up time t

CSU

1.8 ms 1

Power-on reset delay t

POR

65536 t

CLCL

NOTES FOR POWER CYCLE TIMING CHARACTERISTICS

1. Start-up time for crystals varies with load capacitance and manufacturer. Time shown is for an

11.0592 MHz crystal manufactured by Fox Electronics.

2. Reset delay is a synchronous counter of crystal oscillations during crystal start-up. Counting begins

when the level on the XTAL1 input meets the V

IH2

criteria. At 40 MHz, this time is approximately

1.64 ms.

POWER CYCLE TIMING

1 2 ... 50 51 52 53 54 55 56 57 58

Keine Kommentare

Maxim-integrated DS80C390 Bedienungsanleitung Seite 55