The X 86 Microprocessors: Architecture, Programming and Interfacing (8086 to Pentium) 2nd Edition by Pearson

PERIPHERAL INTERFACING–II 10-25

Example 10.12

Write the display RAM control word

i) with auto-increment

ii) without auto-increment

Solution

Here, let us select the first location in the display RAM.

i) With AI = 1, the control word is 1001 0000, i.e., 90H.

ii) With AI = 0 (no auto-increment), the control word is 1000 0000, i.e., 80H.

v) Read FIFO / Sensor RAM

D

7

D

6

D

5

D

4

D

3

D

2

D

1

D

0

0 1 0 AI X A A A

This control word is for setting up the FIFO / SENSOR RAM.

AI – Auto Increment. Irrelevant for scanned keyboard mode but used in sensor

RAM mode.

AAA – Irrelevant for scanned keyboard mode but used in sensor RAM mode.

Example 10.13

Write the control word for ...