---
name: "qflow"
section: "1"
platform: "linux"
package: "qflow"
version: "1.3.17+dfsg.1-3+b1"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/qflow"
---

# qflow(1)

Open-Source Digital Synthesis Flow

## NAME

**qflow** - Open-Source Digital Synthesis Flow

## SYNOPSIS

```
qflow [processes] [options] <module_name>
```

## DESCRIPTION

**This is the main executable for a complete tool chain** **for synthesizing digital circuits starting** **from verilog source and ending in physical layout for a specific target** **fabrication process. In the world of commercial electronics, digital** **synthesis with a target application of a chip design is usually bundled** **into large EDA software systems. As commercial electronics designers need** **to maintain cutting-edge performance, these commercial toolchains get more** **and more expensive, and have largely priced themselves out of all but the** **established integrated circuit manufacturers. This leaves an unfortunate** **gap where startup companies and small businesses cannot afford to do any** **sort of integrated circuit design.**

**Qflow tries to fill this gap.**

## PROCESSES

- **synthesize**

  **Synthesize verilog source**

- **place**

  **Run initial placement**

- **sta**

  **Static timing analysis**

- **route**

  **Run placement and route**

- **decongest**

  **Run congestion analysis, final place and route**

- **clean**

  **Remove temporary working files**

- **display**

  **Display routed result**

- **build**

  **Run scripts synthesize to route**

- **all**

  **Run scripts synthesize to display**

## OPTIONS

- **-T, --tech \<name\>**

  **Use technology \<name\>  (Default: osu035)**

- **-p, --project \<name\>**

  **Project root directory is \<name\>**

## USAGE

**The simplest way to use qflow is to be in a directory with one Verilog file called input.v and execute:**

```
   qflow build input.v
```

**This will run all the necessary steps in order to produce a layout of the specified Verilog file. If only certain steps are desired, one may first run:**

```
   qflow input.v
```

**and then open qflow\_exec.sh and uncomment the desired steps, and at last run:**

```
   ./qflow_exec.sh
```

**It is also possible to change other "project-specific" details in the files qflow\_vars.sh and project\_vars.sh which also have been created in the current directory.**

## TECHNOLOGY

**qflow looks for technology files under /usr/share/qflow/tech. A shell script must be placed in a sub directory there declaring where each of the technology files are located:**

```
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME].sh
```

**Usually, the files needed are placed in the following locations:**

```
  /usr/share/qflow/tech/[TECHNAME]/SCN4M_SUBM.20.tech
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME].magicrc
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME].prm
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME]_stdcells.v
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME]_stdcells.lef
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME].par
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME]_stdcells.sp
  /usr/share/qflow/tech/[TECHNAME]/[TECHNAME]_stdcells.lib
```

**If no technology name is specified on the command line with the -T/--tech option, it will attempt to use the default technology which is "osu035".**

**If the technology files are located somewhere else, this can be specified in qflow\_vars.sh which is created when running qflow. The variables "techdir" and "techname" must be changed accordingly.**

## AUTHOR

**This manual page was written by Ruben Undheim \<ruben.undheim@gmail.com\> for the Debian project (and may be used by others).**