Hp-Ib Interface - HP 340 Series Service Manual

HP-IB Interface
Hewlett-Packard Interface Bus (HP-IB) is HP's version of the IEEE 488 interface standard and
is much like HP-IB implementations on other HP 9000 Series 200/300 computers. It uses a
TMS9914 HP-IB controller which allows data transfer rates up to 450 Kbytes/second. The
TMS9914 is a menlory-mapped I/O device which is multiple-mapped within a 64 Kbyte block
of memory.
Two registers control hardware which can generate an interrupt as a result of a HP-IB device
responding to a parallel poll. It has the ability to generate an interrupt from a parallel poll
response. For this feature, two registers external to the TMS9914 are used. These registers are
in addition to the two external registers that exist for internal HP-IB interfaces in other Series
200 computers.
All registers associated with the HP-IB are multiple mapped within a 64 Kbyte block of memory
in the internal I/O address range.
One configuration switch for HP-IB system controller is on the processor board. Accessible
through the rear panel, the SC switch is set to 1 if the SPU is the system controller or 0 if not.
Configuration Switches
On the rear panel
1
a port through which a pointed object may be used to set the configuration
switches.
Four DIP switches configure the processor board interfaces for:
• RS-232 Modem EN able.
• RS-2:32 REMemote enable.
• HP-IB systenl controller.
•
LAl\~
local/remote
Table 3-2 has a picture and explains the use of these switches.
Functional Description
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