Appendix
A
A-1
Dualport Layout
The following description of the dual port gives address, mnemonic, size,
read/write permission for host/KTx, and a description of dual-port
variables. Addresses :000-016H are common for all KTx protocols and are
not necessarily applicable to the scanner protocol. These are indicated by a
blank description field.
Address
Mnemonic
Size
Host
KT
x
Description
:000H
boot_code
4
R/W
R
Must be initialized by the host to hex C3 00 00 00.
:004
link_state
1
:005
link_address
1
:006
link_protocol
1
R/W
R
Must be initialized by the host to 06h.
:007
link_baud_rate
1
R/W
R
Must be initialized by the host to FC (57.6k), FD (115.2K),
or FE (230.4K)
:008
reserved1
1
:009
config_data
1
R/W
R
Allows the host to configure the scanner operation.
Bit 0: when high, the scanner will interrupt the host at the
end of each time through the scan list.
Bit 1: reserved.
Bit 2: when high, the scanner will interrupt the host
whenever there is a change in the Input Image Table.
Bits 3-7: unused.
:00A
init_status
1
R
W
While initialization is in progress this will be set to 1.
If initialization fails an error code will be written here,
otherwise 0 will be written here to indicate success.
:00B
running_status
1
R/W
W
Host clears these bits:
Bit 0: when high, the scanner is at the end of the scan list.
Bit 1: when high, an adapter replied to wrong address.
Bits 2-7: not used.
:00C
int_status_to_host
1
R
W
Used by the KT
x
to tell the host the type of interrupt the
KT
x
just sent to the host.
:00D
int_status_from_host
1
R/W
R/W
Used by the KT
x
and host for handshaking. The host may
interrupt the KT
x
with one of two interrupt types:
COMMAND (01) or CONFIRMATION_PROCESSED (02).
The KT
x
will write INTERRUPT_PROCESSED (0) when it
has finished processing the interrupt from the host.
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