Programming Model
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3-39
3
Programming the Printer Port
This section provides addresses and bit level descriptions of the printer
port control, status, and data registers.
Printer ACK Interrupt Control Register
IL2-IL0
These three bits select the interrupt level for the printer
ACK. Level 0 does not generate an interrupt.
ICLR
In edge-sensitive mode, writing a logic 1 to this bit clears
the INT status bit. This bit has no function in level-
sensitive mode. This bit is always read as zero.
IEN
When this bit is high, the interrupt is enabled. The
interrupt is disabled when this bit is low.
INT
When this bit is high, a printer ACK interrupt is being
generated at the level programmed in IL2-IL0 (if
nonzero).
E/L*
When this bit is high, the interrupt is edge-sensitive. The
interrupt is level-sensitive when this bit is low.
PLTY
When this bit is low, interrupt is activated by a falling
edge/low level on the PRACKI* pin.
When this bit is high, interrupt is activated by a rising
edge/high level on the PRACKI* pin.
Note that if this bit is changed while the E/L* bit is set (or
is being set), an ACK interrupt may be generated. This can
be avoided by setting the ICLR bit during write cycles that
change the E/L* bit.
ADR/SIZ
$FFF42030 (8 bits)
BIT
31
30
29
28
27
26
25
24
NAME
PLTY
E/L*
INT
IEN
ICLR
IL2
IL1
IL0
OPER
R/W
R/W
R
R/W
C
R/W
R/W
R/W
RESET
0 PL
0 PL
0 PL
0 PL
0 PL
0 PL
0 PL
0 PL
Summary of Contents for MVME1X7P
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Page 90: ...1 64 Computer Group Literature Center Web Site Programming Issues 1 ...
Page 248: ...3 50 Computer Group Literature Center Web Site PCCchip2 3 ...
Page 286: ...4 38 Computer Group Literature Center Web Site MCECC Functions 4 ...
Page 288: ...A 2 Computer Group Literature Center Web Site Summary of Changes A ...
Page 316: ...Index IN 14 Computer Group Literature Center Web Site I N D E X ...