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USER SELECTABLE OPTIONS
The Am96/4116A is designed as a general purpose 16 bit micro computer;
opt
i
ona
1
j umperi ng fac i
1
i ty is prov i ded to ta i
1
or board operat i on to
specific use.
Jumpers must be in the correct positions prior to bOard
operation.
The following paragraphs provide instructions for optional
jumper configurations.
MEMORY EXPANSION
The Am96/4116A has the capability of bank selecting up to sixteen 32k
byte blocks of off-board memory, for a maximum of 152k bytes of
external RAM and/or ROM.
Parallel I/O port C bits 0 to 3, are used to
select the off-board memory.
However, off-board memory must not occupy
the same logical address space as the on-board RAM.
If on-board RAM is
in the upper 32k (8000 to FFFF hex), then off-board memory must occupy
the space from 0000 to 7FFF hex.
Table 2-1 lists the jumpers
available.
TABLE 2-1.
MEMORY EXPANSION JUMPERS
SIGNAL
JUMPER PIN (s)
PCO*
10
PCl*
12
PC2*
14
PC4*
16
ADRF*
62-63
ADI0*
65, 36-37
ADll*
68, 38-39
ADI2*
58, 40-41
ADI3*
59,42-43
N/S*
66
I-FETCH*
69
For exampl e, to connect PCO* to the Mul ti bus ADI0* pi n, connect a
jumper from pin 10 to 65, and a jumper from 36 to 37. To connect PCl*
to ADll*, connect a jumper from 12 to 68 and another from 38 to 39.
Two addi tiona
1 1
i nes, defi ned by the CPU, are ava i
1
ab
1
e at jumper pi ns
. to expand the memory to a maximum of 160K bytes.
The signals are
I-FETCH* (code) and N/S* (Normal/System).
The I-FETCH* signal provides
the capability of having two separate areas of memory one for code and
one for data.
The N/S*signal provides for two additional areas of
memory, one for system use and one for normal (user) functions.
The
functions of I-FETCH* and N/S* can be combined as shown in figure 2-1.
The blocks shown in figure 2-1 can occupy the same
logical area of
memory, though the physical locations will be different.
2-2
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