Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Writing a Host Communications Program
389
EQUn (Position Compare for Channel n): The EQUn line contains the state of the position-compare
output for Servo Channel n of the Turbo PMAC. This line can be toggled by the automatic action of the
encoder counter’s compare circuitry, or by writing directly to control bits for this circuitry, which permits
the use of this signal as a software-generated interrupt from Turbo PMAC programs.
output for Servo Channel n of the Turbo PMAC. This line can be toggled by the automatic action of the
encoder counter’s compare circuitry, or by writing directly to control bits for this circuitry, which permits
the use of this signal as a software-generated interrupt from Turbo PMAC programs.
In a Turbo PMAC, the EQUn line can be used for software-generated interrupts by writing to the EQU
out invert-enable bit for the channel (bit 13 of the channel’s control/status word, suggested M-variable
Mxx13). When the encoder counter and the compare register values do not match, setting this bit to 1
takes this signal high, which can generate an interrupt; setting it to 0 takes the signal low.
out invert-enable bit for the channel (bit 13 of the channel’s control/status word, suggested M-variable
Mxx13). When the encoder counter and the compare register values do not match, setting this bit to 1
takes this signal high, which can generate an interrupt; setting it to 0 takes the signal low.
In a Turbo PMAC2, this line can be used for software-generated interrupts with the direct-write feature.
This is a two-step process. First, the value to be output is written to the direct-write value bit (bit 12 of
the channel’s control word, suggested M-variable Mxx12). Next, a 1 is written to the direct-write enable
bit (bit 11 of the channel’s control word, suggested M-variable Mxx11).
This is a two-step process. First, the value to be output is written to the direct-write value bit (bit 12 of
the channel’s control word, suggested M-variable Mxx12). Next, a 1 is written to the direct-write enable
bit (bit 11 of the channel’s control word, suggested M-variable Mxx11).
With the suggested M-variable definitions, the code to trigger a software-generated interrupt using EQU1
is:
is:
M112=1
; Prepare to set EQU1 high
M111=1
; Enable writing of M112 value to EQU1 (M111 is self-clearing)
To clear EQU1 in advance of the next interrupt, the code is:
M112=0
; Prepare to set EQU1 low
M111=1
; Enable writing of M112 value to EQU1 (M111 is self-clearing)
If I56 and I58 are both set to 1 to enable DPRAM ASCII communications with interrupts, a (non-
Ultralite) Turbo PMAC will generate an interrupt on the EQU1 line each time it has loaded a response
line into the DPRAM ASCII response buffer. With this function active, no other use of the EQU1 line
should be made.
Ultralite) Turbo PMAC will generate an interrupt on the EQU1 line each time it has loaded a response
line into the DPRAM ASCII response buffer. With this function active, no other use of the EQU1 line
should be made.
AXEXPn (Axis Expansion EQU Line): The AXEXP0 and AXEXP1 lines on a Turbo PMAC-PC board
are inputs that can be used to bring in selected EQUn lines for interrupt purposes from an Acc-24P Axis
Expansion board. Which EQU line is used from the Acc-24P board is determined by jumpers on the Acc-
24P board. The AXEXPn TTL-level lines can also be driven by other external signals.
are inputs that can be used to bring in selected EQUn lines for interrupt purposes from an Acc-24P Axis
Expansion board. Which EQU line is used from the Acc-24P board is determined by jumpers on the Acc-
24P board. The AXEXPn TTL-level lines can also be driven by other external signals.
MIn (Machine Input n): The MI1 and MI2 lines are general-purpose 5V-24V inputs on Turbo PMAC
controllers. With the appropriate jumpers selected, they can be used to interrupt the host computer.
controllers. With the appropriate jumpers selected, they can be used to interrupt the host computer.
CTRLn (Control Output n): The CTRL0 and CTRL1 signals are generally unused lines on Turbo
PMAC2 controllers. On Turbo PMAC2 Ultralite controllers, they can be used for software-generated
interrupts. They can be made outputs by setting bits 8 and 9, respectively, of X:$078403 to 1; then their
sense can be changed by writing to the inversion-control bits for these lines at bits 8 and 9 of X:$078407,
respectively.
PMAC2 controllers. On Turbo PMAC2 Ultralite controllers, they can be used for software-generated
interrupts. They can be made outputs by setting bits 8 and 9, respectively, of X:$078403 to 1; then their
sense can be changed by writing to the inversion-control bits for these lines at bits 8 and 9 of X:$078407,
respectively.
If I56 and I58 both are set to 1 to enable DPRAM ASCII communications with interrupts, a Turbo
PMAC2 Ultralite will generate an interrupt on the CTRL0 line each time it has loaded a response line into
the DPRAM ASCII response buffer.
PMAC2 Ultralite will generate an interrupt on the CTRL0 line each time it has loaded a response line into
the DPRAM ASCII response buffer.
WDO (Watchdog Output): The watchdog signal goes true when the Turbo PMAC watchdog timer trips
and shuts down the card.
and shuts down the card.
Integrated Interrupt Controller
The interrupt controller function on all Turbo PMAC2 boards and all PCI-bus Turbo PMAC boards (1
and 2) is integrated into the bus interface logic. It is modeled after the 8259, but is more simplified and
straightforward.
and 2) is integrated into the bus interface logic. It is modeled after the 8259, but is more simplified and
straightforward.