Real Time Devices AD1200 User Manual page 120

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lnput Control Slgnal Dellnltlon
STE (Strole Input). A "low" on this input loads
data into the input latch.
IBF (lnput Bufler Full F/F)
A "high" on this output indicates that the data has
been loaded into the input latch; in 6ssence, an ac-
knowledgement. IBF is set by STE ingt being low
and is reset by the rising edge of the RD input.
INTR (lntenupt Fequest)
A "high" on this output can be used to interupt the
GPU when an input device is requesting service.
INTR is set by the STB is a "on6", IBF is a "one"
and INTE is a "one". lt is reset by the falling edge of
RD-. This procedure allows an input device to re-
quest service from the CPU by simply strobing its
data into the port.
INTE A
Controlled by bit set/reset of PCa.
INTE B
Gontrolled by bit set/reset of PC2.
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Flgure 8. lrlODE I Input
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Flgure 9.llODE 1 (Strobed Input)
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