The document describes an IC245 bidirectional buffer and IC373 octal latch. The IC245 can drive data in both directions on a bus, sourcing 15mA and sinking 24mA. It contains 16 non-inverting buffers that are controlled by a DIR pin to determine the direction of data flow. The IC373 octal latch is used to separate address and data on a bus and is controlled by an ALE signal. It also describes the minimum and maximum mode read and write bus cycles for an 8086-based system using these chips.

1. IC245 Bidirectional Buffer
•Also called as Octal bus Transceiver
•Bidirectional bus increases the
current driving capacity of data bus
•Each buffer can sink 24mA and
source 15mA.
•Consists of 16 non inverting buffers,
eight for each direction with tri-state
outputs.
•G is the enable pin, when G=0,DIR is
chosen.
•Direction of data pin decided by DIR
pin
•When DIR = 1, Data A bus  B bus
•When DIR =0, Data B bus  A bus

2. IC373 Octal latch
•Used for the separation of valid addresses from
address/data bus
•Controlled by the ALE signal of microprocessor
•Latch is controlled by E input (STB input) which is
connected to the clock input of D f/f.
•Buffer is controlled by OE pin

3. Minimum Mode of 8086 Based System
Octal Latch
Transceiver

4. Minimum Mode Read bus cycle

5. Minimum Mode Write bus cycle

6. Maximum Mode of 8086 Based System
Octal Latch
Transceiver

7. Maximum Mode Read bus cycle

8. Maximum Mode Write bus cycle