ID 683819
Date 10/13/2021
Public

## 6.5. Tcl interface for the In-System Sources and Probes Editor

To support automation, the In-System Sources and Probes Editor supports the procedures described in this chapter in the form of Tcl commands. The Tcl package for the In-System Sources and Probes Editor is included by default when you run quartus_stp.

The Tcl interface for the In-System Sources and Probes Editor provides a powerful platform to help you debug your design. The Tcl interface is especially helpful for debugging designs that require toggling multiple sets of control inputs. You can combine multiple commands with a Tcl script to define a custom command set.

Table 34.  In-System Sources and Probes Tcl Commands
Command Argument Description
start_insystem_source_probe -device_name <device name> -hardware_name <hardware name> Opens a handle to a device with the specified hardware.

Call this command before starting any transactions.

get_insystem_source_probe_instance_info -device_name <device name> -hardware_name <hardware name> Returns a list of all ALTSOURCE_PROBE instances in your design. Each record returned is in the following format:

{<instance Index>, <source width>, <probe width>, <instance name>}

read_probe_data -instance_index <instance_index>-value_in_hex (optional) Retrieves the current value of the probe.

A string is returned that specifies the status of each probe, with the MSB as the left-most bit.

read_source_data -instance_index <instance_index>-value_in_hex (optional) Retrieves the current value of the sources.

A string is returned that specifies the status of each source, with the MSB as the left-most bit.

write_source_data -instance_index <instance_index> -value <value> -value_in_hex (optional) Sets the value of the sources.

A binary string is sent to the source ports, with the MSB as the left-most bit.

end_insystem_source_probe None Releases the JTAG chain.

Issue this command when all transactions are finished.

The example shows an excerpt from a Tcl script with procedures that control the ALTSOURCE_PROBE instances of the design as shown in the figure below. The example design contains a DCFIFO with ALTSOURCE_PROBE instances to read from and write to the DCFIFO. A set of control muxes are added to the design to control the flow of data to the DCFIFO between the input pins and the ALTSOURCE_PROBE instances. A pulse generator is added to the read request and write request control lines to guarantee a single sample read or write. The ALTSOURCE_PROBE instances, when used with the script in the example below, provide visibility into the contents of the FIFO by performing single sample write and read operations and reporting the state of the full and empty status flags.

Use the Tcl script in debugging situations to either empty or preload the FIFO in your design. For example, you can use this feature to preload the FIFO to match a trigger condition you have set up within the Signal Tap logic analyzer.
Figure 105. DCFIFO Example Design Controlled by Tcl Script

## Setup USB hardware  - assumes only USB Blaster is installed and
## an FPGA is the only device in the JTAG chain
set usb [lindex [get_hardware_names] 0]
set device_name [lindex [get_device_names -hardware_name $usb] 0] ## write procedure : argument value is integer proc write {value} { global device_name usb variable full start_insystem_source_probe -device_name$device_name -hardware_name $usb #read full flag set full [read_probe_data -instance_index 0] if {$full == 1} {end_insystem_source_probe
return "Write Buffer Full"
}
##toggle select line, drive value onto port, toggle enable
##bits 7:0 of instance 0 is S_data[7:0]; bit 8 = S_write_req;
##bit 9 = Source_write_sel
##int2bits is custom procedure that returns a bitstring from an integer     ## argument
write_source_data -instance_index 0 -value /[int2bits [expr 0x200 | $value]] write_source_data -instance_index 0 -value [int2bits [expr 0x300 |$value]]
##clear transaction
write_source_data -instance_index 0 -value 0
end_insystem_source_probe
}
start_insystem_source_probe -device_name $device_name -hardware_name$usb
if {[regexp {1........} $empty]} { end_insystem_source_probe return "FIFO empty" } ## toggle select line for read transaction ## Source_read_sel = bit 0; s_read_reg = bit 1 ## pulse read enable on DC FIFO write_source_data -instance_index 1 -value 0x1 -value_in_hex write_source_data -instance_index 1 -value 0x3 -value_in_hex set x [read_probe_data -instance_index 1 ] end_insystem_source_probe return$x
}