Table of Contents
Advertisement
RxRDY
Recei ver Ready i nd"; cates the Am9551 has recei ved a
character on 'i ts ser'j al input and is ready to transfer
i
t
to the CP U•
TxE
Transmi tter
Empty
signals
the
processor
that
the
transmit register is empty.
PE
OE
FE
SYNDET
DSR
Parity Error indicates the character stored in the
received character buffer was received with an incorrect
number of binary 1 bits.
Overrun fl ag is set 'when a byte stored in the recei ver
character register is overwritten with a new byte before
being transferred to the processor.
Framing Error indicates the asynchronous mode
byte
stored in the recei ver character buffer was recei ved
with incorrect character bit format.
When Sync Detect is set for internal sync detect, this
bit indicates character sync has been acheived and the
Am9551 is ready for data.
Data Set Ready is set by the externa
1
Data Set Ready
Signal to indicate the communications data set is ready.
7
6
5
4
3
2
o
- I t - -
Bit No.
TxEN
1 :;: Enable transmission
0:;: Disable transmission
DTR
1 :;: DTR output is forced to 0
RxE
1 :;: Enable RxRDY
o :;:
Disable RxRDY
SBRK
1 :;:
TxD is forced low
o :;:
Normal operation
ER
1 :;:
Resets all error flags in
Status register (PE, OE, FE)
RTS
1 :;: RTS output is forced to 0
IR
1 :;:
Reset format
EH
1 :;: Enter HUNT mode
Figure
3-Ei.
Am9551 Command Instruction Word Format
3-7
Advertisement
Table of Contents
