82C55A Datasheet, PDF (6/23 Pages) Intel Corporation – CHMOS PROGRAMMABLE PERIPHERAL INTERFACE

82C55A
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Figure 7 Bit Set Reset Format
Interrupt Control Functions
When the 82C55A is programmed to operate in
mode 1 or mode 2 control signals are provided that
can be used as interrupt request inputs to the CPU
The interrupt request signals generated from port C
can be inhibited or enabled by setting or resetting
the associated INTE flip-flop using the bit set reset
function of port C
This function allows the Programmer to disallow or
allow a specific I O device to interrupt the CPU with-
out affecting any other device in the interrupt struc-
ture
INTE flip-flop definition
(BIT-SET) INTE is SET Interrupt enable
(BIT-RESET) INTE is RESET Interrupt disable
Note
All Mask flip-flops are automatically reset during
mode selection and device Reset
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