
EXM-31 Hardware Reference
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The interrupt select is as follows:
Bit 3
Bit 2
Bit 1
Interrupt
0 0 0 IRQ9
0 0 1 IRQ3
0 1 0 IRQ4
0 1 1 IRQ5
1 0 0 IRQ7
1 0 1 IRQ11
1 1 0 IRQ12
1 1 1 IRQ15
Table 2. OB1 Settings.
For example, a typical OB1 value is
07
h (0000 0111) indicating the card is enabled at
IRQ5.
Note that interrupts cannot be disabled. Make sure that the IRQ chosen for the
EXM-31 does not conflict with any other modules that use an IRQ. Some common
IRQs to avoid are the following:
IRQ3
if already using COM2
IRQ4
if already using COM1
IRQ6
if using floppy disk controller
IRQ7
if
using
LPT1
OB2
is used to select the base address.
Reserved
bit 7
Base Address Select
(bits 6-0)
Set to 1
see below
Figure 4. OB2 Register.
Base Address
specifies the base address of the UART I/O registers. This value is
matched against SA[9..3] to provide an I/O chip select.
Содержание EXM-31
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