Intel 80C188EC User Manual page 381

INPUT/OUTPUT PORTS
From Integrated
Peripheral
Read Port
Data latch
Write Port
Data Latch
Read Port
Pin State
Read Port
Direction Control
Internal Data
Bus (F-Bus)
Write Port
Direction
Read Port
Direction
Write Port
Control
To Integrated
Peripheral
Figure 13-1. Simplified Logic Diagram of a Bidirectional Port Pin
13-2
Q
D
Q
Port Data Latch
Q
D
Q
Port Direction Latch
Q
D
Q
Port Control Latch
Peripheral
Direction Control
Port/Peripheral
Data Multiplexer
Output Driver
I0
Q
I1
S
SYNC
I0
Q
I1
S
Pin
A1247-0A