Intel 386 - Manual (Page 409)

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