Interface Guide: STW-PC Series PCIe Timing Cards

Overview

The BRIDZA STW-PC series PCIe timing cards provide precision timing synchronization for computer systems, enabling sub-nanosecond synchronization accuracy for data acquisition, telecommunications, and financial timestamping applications. These cards are available in PCIe 2.0 x1, x4, and x8 form factors to accommodate various system requirements.

Supported Models

Board Layout

 ┌─────────────────────────────────────────────────────────────────────┐
 │ STW-PC4 PCIe Timing Card │
 │ │
 │ ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐ │
 │ │PCIe Gold│ │ FPGA │ │ TCXO/ │ │ Flash │ │
 │ │ Finger │ │ Xilinx │ │ OCXO │ │ Memory │ │
 │ │ │ │ Artix-7 │ │ │ │ │ │
 │ └────┬────┘ └────┬────┘ └────┬────┘ └─────────┘ │
 │ │ │ │ │
 │ │ │ │ │
 │ └────────────┼────────────┘ │
 │ │ │
 │ ┌───────────────┼───────────────┐ │
 │ │ │ │ │
 │ ┌──┴──┐ ┌────┐ ┌────┐ ┌────┐ ┌────┐ │
 │ │PPS │ │10M │ │10M │ │TOD │ │EXT │ │
 │ │ IN │ │ IN │ │OUT │ │RS232│ │1PPS│ │
 │ │ SMA │ └──○─┘ └──○─┘ │ DB9 │ │ SMA│ │
 │ └──○───┘ └────┘ └──○───┘ │
 │ │
 │ Bracket: Full height PCIe │
 │ │
 └──────────────────────────────────────────────────────────────────────┘

PCIe Interface

Gold Finger Pinout (x4/x8)

Electrical Specifications

External Connectors

1. 1PPS Input

2. 1PPS Output

3. 10MHz Input

4. 10MHz Output

5. TOD Serial Interface

DB9 Pinout:

Linux Driver Installation

Requirements

• Linux kernel 3.2 or higher
• GCC compiler
• make

Installation Steps

# Download driver package
tar -xzf stw-pc-drivers-linux-v2.0.tar.gz
cd stw-pc-drivers-linux-v2.0

# Compile driver
make

# Install driver
sudo make install

# Load driver
sudo modprobe stw_pc

# Check device
dmesg | grep STW-PC

Device Nodes

After installation, devices appear as:

• /dev/stw_pc0 - First card
• /dev/stw_pc1 - Second card (if present)

Windows Driver Installation

Installation Steps

• Download driver package from BRIDZA website
• Extract to temporary folder
• Connect STW-PC card to PCIe slot
• Windows will prompt for driver
• Select "Browse my computer"
• Navigate to extracted folder
• Complete installation

Device Manager

After installation, device appears as:

• "BRIDZA STW-PC Timing Card" under System Devices

API Reference

C Library Functions

#include 

// Open device
int stw_pc_open(int card_num);

// Close device
int stw_pc_close(int fd);

// Read timestamp
int stw_pc_read_timestamp(int fd, uint64_t *timestamp_ns);

// Read 1PPS counter
int stw_pc_read_pps_counter(int fd, uint64_t *count);

// Set 10MHz output
int stw_pc_set_10mhz_output(int fd, int enable);

// Set 1PPS output
int stw_pc_set_pps_output(int fd, int enable, uint32_t pulse_ns);

// Get device status
int stw_pc_get_status(int fd, stw_pc_status_t *status);

// Example usage
int main() {
 int fd = stw_pc_open(0);
 if (fd < 0) {
 printf("Failed to open device\n");
 return -1;
 }
 
 uint64_t timestamp;
 stw_pc_read_timestamp(fd, ×tamp);
 printf("Timestamp: %llu ns\n", timestamp);
 
 stw_pc_close(fd);
 return 0;
}

Python Bindings

import ctypes

lib = ctypes.CDLL("libstw_pc.so")

class STWPCStatus(ctypes.Structure):
 _fields_ = [
 ("locked", ctypes.c_int),
 ("pps_valid", ctypes.c_int),
 ("timestamp_ns", ctypes.c_uint64)
 ]

# Open device
fd = lib.stw_pc_open(0)

# Read status
status = STWPCStatus()
lib.stw_pc_get_status(fd, ctypes.byref(status))
print(f"Locked: {status.locked}, PPS Valid: {status.pps_valid}")

# Close device
lib.stw_pc_close(fd)

Mechanical Dimensions

 PCIe Bracket: Standard full-height (111.15mm)
 Card Length: 167.65mm max
 PCB Thickness: 1.6mm
 
 ┌───────────────────────────────────────────────┐
 │ │
 │ [PCIe Gold Finger] │
 │ │ │
 │ └───────────────────────────────────────┐ │
 │ │ │
 │ ┌───────────────────────────────────┐ │ │
 │ │ │ │ │
 │ │ FPGA + Clock Circuit │ │ │
 │ │ │ │ │
 │ └───────────────────────────────────┘ │ │
 │ │ │
 │ [SMA Connectors] │ │
 │ │ │
 └───────────────────────────────────────────┘

Troubleshooting

Download Resources

• STW-PC Datasheet
• Linux Driver Package
• Windows Driver
• C API Documentation

Document Version: 1.0

Last Updated: 2026-05-24

BRIDZA Technologies