Intel 386 - Manual (Page 421)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
13-22
Figure 13-20. SSIO Control 1 Register (SSIOCON1)
SSIO Control 1
SSIOCON1
(read/write) Expanded Addr:
ISA Addr:
Reset State: F486H
—
C0H
7 0
TUE THBE TIE TEN ROE RHBF RIE REN
Bit
Number
Bit
Mnemonic
Function
7 TUE Transmit Underrun Error:
The transmitter sets this bit to indicate a transmit underrun error in the
TEN transfer mode. Clear this bit to clear the error flag. If a one is written
to TUE, it is ignored and TUE retains its previous value.
6 THBE
(read only bit) Transmit Holding Buffer Empty:
The transmitter sets this bit when the transmit buffer contents have been
transferred to the transmit shift register, indicating that the buffer is now
ready to accept new data. Writing data to the transmit buffer clears
THBE. When this bit is clear, the buffer is not ready to accept any new
data.
5 TIE Transmitter Interrupt Enable:
0 = Clearing this bit prevents the Interrupt Control Unit from sensing
when the transmit buffer is empty.
1 = Setting this bit connects the transmit buffer empty internal signal to
the Interrupt Control Unit.
4 TEN Transmitter Enable:
0 = Disables the transmitter.
1 = Enables the transmitter.
3 ROE Receive Overflow Error:
The receiver sets this bit to indicate a receiver overflow error. Write zero
to this bit to clear the flag.
If a one is written to ROE, the one is ignored and ROE retains its
previous value.
2 RHBF
(read only bit) Receive Holding Buffer Full:
The receiver sets this bit when the receive shift register contents have
been transferred to the receive buffer.
Reading the buffer clears this bit.
1 RIE Receive Interrupt Enable:
0 = Clearing this bit prevents the Interrupt Control Unit from sensing
when the receive buffer is full.
1 = Setting this bit connects the receiver buffer full internal signal to the
Interrupt Control Unit.
0 REN Receiver Enable:
0 = Clearing this bit disables the receiver.
1 = Setting this bit enables the receiver.