Intel 386 User Manual

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
13-10
Figure 13-9. Interrupt Service Routine for Transmitting Data Using Interrupts
A3398-01
THBE=1
?
Error
Routine
SSIO Transmitter
Causes Interrupt
Disable Interrupts While
Transmitting Data
No
Write Data to Buffer
(SSIOTBUF)
Yes
Enable Interrupts
Exit Interrupt Service Routine
Enable Transmitter
TEN=1
Delay To Allow Transmitter
To Shift First Bit Out
Disable Transmitter
TEN=0

Intel 386 Specifications

General

Architecture	x86
Clock Speed	12 MHz to 40 MHz
Transistor Count	275, 000
Data Bus Width	32-bit
Address Bus Width	32-bit
Instruction Set	x86
Introduced	1985
Maximum Memory	4 GB
Operating Modes	Real mode, Protected mode, Virtual 8086 mode
MMU	Yes
Voltage	5V
Model	Intel 386
Package	PGA
Process	1.5 μm to 1 μm