Real Time Devices AD1200 User Manual page 113

intef
82C55A
ar.Drttctlilat oltr .|a
or Do
t6
ar
atttt
231256-9
RESSI
ilTERTAT
OATA |l{
irTElxAL
OATA OUT
EnEtx t
POFr qC
?IN
NYESIAL
OATA
'NOTE:
wn
Port pins loaded with more than 20 pF capacitanc€ may not have
their rogic
231zfi-4
level guaranteed following a hardware resel.
Flgure 3' 82c55A Block Dlagram Showlng Data Bus Bufferand Read/wrlte
controtLogtc Fu;[o;
Flgure 4. Port A, B, C, Bus-hold Conllguration
3-127