Command Pass Through Register (CPTR)
VMEbus Address:
Base A 11B (hex)
Attributes:
Read Only, Internal to TLC
R
7
6
5
4
3
2
1
0
CPT7
CPT6
CPT5
CPT4
CPT3
CPT2
CPT1
CPT0
Bit
Mnemonic
Description
7-0r
CPT[7-0]
Command Pass Through Bits 7 through 0
These bits are used to transfer undefined multiline GPIB command
messages from the GPIB DIO lines to the computer. When the CPT
feature is enabled (CPT ENABLE=1, AUXRB[0]w), any GPIB
Primary Command Group (PCG) message not decoded by the TLC is
treated as an undefined command. The multiline GPIB commands
recognized by the
µ
PD7210 are listed in Table 4-3. All GPIB
Secondary Command Group (SCG) messages following an undefined
GPIB PCG message are also treated as undefined. When an undefined
GPIB message is encountered, it is held in the CPTR and the TLC
Acceptor Handshake function is held off (in ACDS) until the Valid
auxiliary command is written to the AUXMR. The CPTR is also used
to inspect secondary addresses when mode 3 addressing is used. The
TLC Acceptor Handshake function is held off (in ACDS) until the
Valid or Non-Valid auxiliary command is written to the AUXMR.
Table 4-3. Multiline GPIB Commands Recognized by the
µ
PD7210
Hex Number
Message
Description
01
GTL
Go To Local
04
SDC
Selected Device Clear
05
PPC
Parallel Poll Configure
08
GET
Group Execute Trigger
09
TCT
Take Control
11
LLO
Local Lockout
14
DCL
Device Clear
(continues)