Texas Instruments 990 Maintenance Manual page 37

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4.3.l.6 CRUDATAIN. CRUDATAIN is serial information from the module to the computer.
The I 6 bits of information represented by CRUDA TAIN are addressable and provide data,
status, and interrupts to the computer. Figure 4-7 illustrates the information contained by
CRUDATAIN.
Data Character.
The first eight bits of information are data bits to be transmitted to the
computer.
Transmit Jn Progress ( XMTl.'VGJ.
Logic 1 active.
Timing t:rror (T/MERR).
Logic 1 active.
RePerse Channel Receil'e ( RCR ).
Logic I active.
MODULE TO CPU MEMORY WORD
OR
(DATA TRANSFER
IS SERIAL)
1 ON
0
OFF
:K WITH KITS 22651SO-OOO1/0002,
RCR BECOMES RING INDICATOR (RI)
(A)133024A
2
3
4
8
9
A
8
c
D
MODULE INTERNAL BIT ADDRESS
LSB
RECEIVED CHARACTER
XMTING (TRANSMIT IN PROGRESS)
TIMERR (TIMING ERROR)
s
RCR*(RE VERSE CHANNEL RECEIVE) T
WRQ (WRITE REQUEST)
A
RRQ (READ REQUEST)
T
DCD (DATA CARRIER DETECT)
u
DSR (DATA SET READY)
INT (INTERRUPT)
Figure 4- 7. Full Duplex TTY /EIA Module Addressable Output Lines
Change 1
30
Digital Systems Division