Reference Manual
Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables 174
Each variable I5061 – I5076 is matched with the I-variable numbered 20 higher (e.g. I5081 for I5061) to
specify which channel of the muxed A/D-converter is to be used, and how that channel is to be read. Up
to 8 of these I-variable pairs must be used to read all 8 channels of a muxed A/D converter – the eight
variables in the I5061 – I5076 range will all contain the same address.
The results of the A/D tables are placed in registers at addresses Y:$003400 to Y:$00341F, using bits 12
to 23 of these registers. The value of the A/D converter found in the low 12 bits of the source register is
placed in the register with the even-numbered address; the value of the A/D converter found in the high
12 bits of the source register is placed in the register with the odd-numbered address. The following table
shows the matching between the A/D pointer I-variables and the addresses of the result registers.
I-Variable
Result Address
for Low ADC
Result Address
for High ADC
I-Variable
Result Address
for Low ADC
Result Address
for High ADC
I5061
Y:$003400
Y:$003401
I5069
Y:$003410
Y:$003411
I5062
Y:$003402
Y:$003403
I5070
Y:$003412
Y:$003413
I5063
Y:$003404
Y:$003405
I5071
Y:$003414
Y:$003415
I5064
Y:$003406
Y:$003407
I5072
Y:$003416
Y:$003417
I5065
Y:$003408
Y:$003409
I5073
Y:$003418
Y:$003419
I5066
Y:$00340A
Y:$00340B
I5074
Y:$00341A
Y:$00341B
I5067
Y:$00340C
Y:$00340D
I5075
Y:$00341C
Y:$00341D
I5068
Y:$00340E
Y:$00340F
I5076
Y:$00341E
Y:$00341F
I5061 – I5076 are used at power-on/reset only, so to make a change in the A/D de-multiplexing sources,
change the values of I5061 – I5076, store these new values to non-volatile flash memory with the SAVE
command, and reset the card with the $$$ command.
I5080 A/D Ring Convert Enable
Range: 0 - 1
Units: none
Default: 1
I5080 controls whether the A/D-converter demultiplexing algorithm specified by I5060 – I5076 and
I5081 – I5096 is enabled or not. If I5080 is set to 1, the algorithm is enabled; if I5080 is set to 0, the
algorithm is disabled.
If the saved value of I5060 is greater than 0, specifying that some demultiplexing is to be done, then
I5080 is automatically set to 1 on power-up/reset, so the algorithms are automatically running. By
subsequently setting I5080 to 0, the user can suspend the execution of these algorithms, to be resumed by
setting I5080 back to 1. If the saved value of I5060 is 0, then I5080 is automatically set to 0 on power-
up/reset.
I5081-I5096 A/D Ring Convert Codes
Range: $000000 - $00F00F
Units: None
Default: $000000
I5081 through I5096 contain the convert codes written to the multiplexed A/D converters that are read in
the A/D ring table, as enabled by I5060. The convert codes control which of the multiplexed ADCs at the
address is to be read, and the range of the analog input for that ADC. The ADCs can be on-board the
Turbo PMAC with Option 12 and 12A, or off-board with an Acc-36P/V. The Turbo PMAC address of
the ADC to be read is set by the I-variable number 20 less (e.g. I5061 determines the address of the ADC
whose convert code is set by I5081). The number of ADC converters in the ring is determined by I5060.
I5081-I5096 are 24-bit values, represented by 6 hexadecimal digits. Legitimate values are of the format
$00m00n, where m and n can take any hex value from 0 through F.