user manual

SECTION CONTENTS
8 - 2 PORT A MOTOROLA
SECTION 8.1 PORT A OVERVIEW ..................................................................3
SECTION 8.2 PORT A INTERFACE .................................................................3
8.2.1 Read/Write Control Signals .................................................................5
8.2.1.1 Program Memory Select (PS) .....................................................5
8.2.1.2 Data Memory Select (DS) ...........................................................5
8.2.1.3 X/Y Select (X/Y) ..........................................................................5
8.2.2 Port A Address and Data Bus Signals ................................................5
8.2.2.1 Address (A0–A15) ......................................................................6
8.2.2.2 Data (D0–D23) ............................................................................6
8.2.3 Port A Bus Control Signals ..................................................................6
8.2.3.1 Read Enable (RD) ......................................................................6
8.2.3.2 Write Enable (WR) ......................................................................6
8.2.3.3 Port A Access Control Signals ....................................................6
8.2.4 Interrupt and Mode Control .................................................................6
8.2.5 Port A Wait States ...............................................................................6