82C55A Datasheet, PDF (10/23 Pages) Intel Corporation – CHMOS PROGRAMMABLE PERIPHERAL INTERFACE

82C55A
MODE 0 Configurations (Continued)
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Operating Modes
MODE 1 (Strobed Input Output) This functional
configuration provides a means for transferring I O
data to or from a specified port in conjunction with
strobes or ‘‘handshaking’’ signals In mode 1 Port A
and Port B use the lines on Port C to generate or
accept these ‘‘handshaking’’ signals
Mode 1 Basic functional Definitions
 Two Groups (Group A and Group B)
 Each group contains one 8-bit data port and one
4-bit control data port
 The 8-bit data port can be either input or output
Both inputs and outputs are latched
 The 4-bit port is used for control and status of the
8-bit data port
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