Table of Contents

i

INTRODUCTION .................................................................................................................................... i-1

Digital I/O ............................................................................................................................................................... i-3

8254 Timer/Counter ................................................................................................................................................ i-3

What Comes With Your Board ............................................................................................................................... i-3

Board Accessories ................................................................................................................................................... i-3

Using This Manual .................................................................................................................................................. i-4

When You Need Help ............................................................................................................................................. i-4

CHAPTER 1 — BOARD SETTINGS .................................................................................................. 1-1

Factory-Configured Switch and Jumper Settings .................................................................................................. 1-3

P3 — Interrupt and Interrupt Channels (Factory Setting: G Connected; Interrupt Channels Disabled) .......... 1-4

P4 — Interrupt Source Select (Factory Setting: EXT) ..................................................................................... 1-5

P5 — 8254 Timer/Counter Clock Sources (Factory Settings: CLK0-OSC, CLK1-OT0, CLK2-OT1) ........... 1-5

S1 — Base Address (Factory Setting: 300 hex (768 decimal)) ......................................................................... 1-6

S2 — Buffer Bypass Switch (Factory Setting: OPEN (Not Bypassed)) ........................................................... 1-7

F1 — External +5-volt Fuse .............................................................................................................................. 1-7

Pull-up/Pull-down Resistors on Digital I/O Lines ................................................................................................. 1-8

CHAPTER 2 — BOARD INSTALLATION ....................................................................................... 2-1

Board Installation ................................................................................................................................................... 2-3

External I/O Connections ....................................................................................................................................... 2-4

Connecting the Digital I/O ................................................................................................................................. 2-4

Connecting the Timer/Counter I/O .................................................................................................................... 2-4

Connecting the External Interrupt ...................................................................................................................... 2-4

Running the 806DIAG Diagnostics Program ........................................................................................................ 2-5

CHAPTER 3 — HARDWARE DESCRIPTION ................................................................................. 3-1

Digital I/O, 8255 Programmable Peripheral Interface .......................................................................................... 3-3

Timer/Counters ...................................................................................................................................................... 3-4

Interrupts ................................................................................................................................................................ 3-4

CHAPTER 4 — BOARD OPERATION AND PROGRAMMING ................................................... 4-1

Defining the I/O Map ............................................................................................................................................. 4-3

BA + 0: PPI Port A — Digital I/O (Read/Write) .............................................................................................. 4-3

BA + 1: PPI Port B — Digital I/O (Read/Write) .............................................................................................. 4-3

BA + 2: PPI Port C — Digital I/O (Read/Write) ............................................................................................... 4-3

BA + 3: 8255 PPI Control Word (Write Only) ................................................................................................. 4-4

BA + 4: IRQ Enable (Write Only) .................................................................................................................... 4-5

BA + 5: Interrupt Status/Clear (Read/Write) .................................................................................................... 4-5

BA + 6: Reserved .............................................................................................................................................. 4-6

BA + 7: Reserved .............................................................................................................................................. 4-6

BA + 8: 8254 Timer/Counter 0 (Read/Write) ................................................................................................... 4-6

BA + 9: 8254 Timer/Counter 1 (Read/Write) ................................................................................................... 4-6

BA + 10: 8254 Timer/Counter 2 (Read/Write) ................................................................................................. 4-6

BA + 11: 8254 Control Word (Write Only) ..................................................................................................... 4-6