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The Development System can be used for
programming work simultaneously with
execution of programs on the Evaluation
Board.
The PI but serves the AmSYS 8/8
while the P2 bus serves the Evaluation
Board.
In this case, separate consoles
may be needed.
However, commun i cat ion
or transfers between the Evaluation
Board and the Development System re-
quire the HOST program to be in execu-
tion.
2-10. JUMPER OPTIONS
Several jumpers, ill ust rated in fi gure
2-4, can be connected to modi fy the
standard functions of the Evaluation
Board.
There is a Break switch for re-
gaining CPU control, two jumpers for
grounding external I/O devices to the
board, one for t i mi ng an extern a1 de-
vice, one for selecting RS232C or TTY
seri ali nterface , one for enab1i ng an
initialization line, one for enabling
an inhibit line, and one for disabling
the memory-cycle Wait state.
All jumpers are unconnE!cted when the
board is shipped; the jumpers (12, 13)
associated with the Break switch are
connected, but the Break switch itself
is normally open.
Wire-wrapping be-
tween the jumper posts will affect the
board's functions as described below.
/BREAK SWITCH - When pressed, it asyn-
chronously generates a non-maskab1e
interrupt (NMI*) to the CPU, which
forces control back to the Monitor
program.
This circuit is connected
via a trace between jumpers 12 and
13.
If the NMI* line on P2 is to
be used, the Break sW'j tch must be
disabled by cutting the trace con-
necting jumpers 12 and 13.
The
wire-wrap pins at 12 and 13 can be
used to reconnect the Break switch
at a later time.
Jumper 1,2 - Whenjumpered, it connects
the chassi s ground of the external
serial
I/O device at P5 to the
Evaluation-Board ground.
Jumper 3,4 - When jumpered, it connects
the cha ss is ground of the external
serial
I/O device at P6 to the
Evaluation-Board ground.
/ .
Jumper 5,6,7 - Used by the Monitor to
determine baud rate at P6 as fol-
lows:
11 .- (
D'/"'(/./
9600 baud - all open
2400 baud - connect 6 to 5
300 baud - connect 7 to 5
110 baud - connect 6 to 5
and
7 to 5
Jumper 8,9 - When jumpered, it connects
the 2MHz clock (4MHz
+
2) to coun-
ter 0 of the Am8253 counter/timer
circuit, which is available exter-
nally through P5.
'Jumper 10,11 - When j umpered, it con-
nects
the
OUT~
output
of
the
Am8253 at P5 to the NVI*
line,
thereby
generat i ng
peri od i c
non-
vectored interrupt s •
0,/(-/1/
l/
Jumper 12,13 - These jumpers are fac-
tory-connected by a trace to enable
the Break switch.
If NMI* is used
at P2, the trace must be cut.
The
jumpers can be reconnected later by
wire wrapping.
7Jumper U56 - Unplugging and rotating
•
this jumper 180 degrees changes the
P6 interface from RS232C to 20mA
current loop (TTY).
The Am9551 must
be reprogrammed for baud rate if
20mA is used.
vJumper 14,15 - When jumpered, it en-
ables pin 14 on the PI Multibus
connector to be an
INIT* input.
When the INIT* line is low, it re-
sets the CPU, USARTs and parallel
I/O circuit.
2-15
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