Bit Mnemonic Description
3r TPAS Talker Primary Addressed State Bit
TPAS is used when the TLC is configured for extended GPIB
addressing, and, when set, indicates that the TLC has received its
primary GPIB talk address. In extended mode addressing (mode 3
addressing), TPAS=1 indicates that the secondary address being
received as the next GPIB command message can represent the TLC
extended (secondary) GPIB talk address.
2r LA Listener Active Bit
LA is set when the TLC has been addressed or programmed as a GPIB
Listener; that is, the TLC is in the Listener Active State, LACS, or the
Listener Addressed State (LADS). The TLC can be addressed to listen
either by sending its own listen or extended listen address while it is
Controller-In-Charge or by receiving its listen address from another
Controller-In-Charge. It can also be programmed to listen using the
Listen Only (lon) bit in the Address Mode Register (ADMR).
If the TLC is addressed to listen, it is automatically unaddressed to
talk. LA is cleared by pon, or by issuing the Chip Reset auxiliary
command.
1r TA Talker Active Bit
TA is set when the TLC has been addressed or programmed as the
GPIB Talker; that is, the TLC is in the Talker Active State (TACS),
the Talker Addressed State (TADS), or the Serial Poll Active State
(SPAS). The TLC can be addressed to talk either by sending its own
talk or extended talk address while it is CIC or by receiving its talk
address from another CIC. It can also be programmed to talk using the
Talk Only (ton) bit in the ADMR.
If the TLC is addressed to talk, it is automatically unaddressed to
listen. TA is cleared by pon, or by issuing the Chip Reset auxiliary
command.
0r MJMN Major-Minor Bit
The MJMN bit is used to determine whether the information in the
other ADSR bits applies to the TLC major or minor Talker and
Listener functions. MJMN is set to one when the TLC GPIB minor
talk address or minor listen address is received. MJMN is cleared on
receipt of the TLC major talk or major listen address.
Note: Only one Talker and Listener can be active at any one time;
thus, the MJMN bit indicates which, if either, of the TLC
Talker and Listener functions is addressed or active. MJMN is
always zero unless a dual primary addressing mode (mode 1 or
mode 3) is enabled (see Address Mode Register later in this
chapter).