CHAPTER 3 METHODOLOGY 3.1 Overview The Water Monitoring ...

AC CharacteristicsUnder operating conditions, load capacitance for Port 0, ALE/PROG, and PSEN = 100 pF; load capacitance for all otheroutputs = 80 pF.External Program and Data Memory Characteristics12 MHz Oscillator Variable OscillatorSymbolParameterMin Max Min MaxUnits1/t CLCL Oscillator Frequency 0 33 MHzt LHLL ALE Pulse Width 127 2t CLCL -40 nst AVLL Address Valid to ALE Low 43 t CLCL -25 nst LLAX Address Hold After ALE Low 48 t CLCL -25 nst LLIV ALE Low to Valid Instruction In 233 4t CLCL -65 nst LLPL ALE Low to PSEN Low 43 t CLCL -25 nst PLPH PSEN Pulse Width 205 3t CLCL -45 nst PLIV PSEN Low to Valid Instruction In 145 3t CLCL -60 nst PXIX Input Instruction Hold After PSEN 0 0 nst PXIZ Input Instruction Float After PSEN 59 t CLCL -25 nst PXAV PSEN to Address Valid 75 t CLCL -8 nst AVIV Address to Valid Instruction In 312 5t CLCL -80 nst PLAZ PSEN Low to Address Float 10 10 nst RLRH RD Pulse Width 400 6t CLCL -100 nst WLWH WR Pulse Width 400 6t CLCL -100 nst RLDV RD Low to Valid Data In 252 5t CLCL -90 nst RHDX Data Hold After RD 0 0 nst RHDZ Data Float After RD 97 2t CLCL -28 nst LLDV ALE Low to Valid Data In 517 8t CLCL -150 nst AVDV Address to Valid Data In 585 9t CLCL -165 nst LLWL ALE Low to RD or WR Low 200 300 3t CLCL -50 3t CLCL +50 nst AVWL Address to RD or WR Low 203 4t CLCL -75 nst QVWX Data Valid to WR Transition 23 t CLCL -30 nst QVWH Data Valid to WR High 433 7t CLCL -130 nst WHQX Data Hold After WR 33 t CLCL -25 nst RLAZ RD Low to Address Float 0 0 nst WHLH RD or WR High to ALE High 43 123 t CLCL -25 t CLCL +25 ns24AT89S52