Generate a clock from FTDI MPSSE

start_clock.py

from pyftdi.ftdi import Ftdi

# Generate a clock output from the D1 pin of an FTDI device that support MPSSE mode (e.g. 232H or 2232H, among others)
# The clock runs continuously, assuming nothing is connected to D4 that will pull it low

# Which device and which port to use for dual port devices (e.g. 2232H)
# See https://eblot.github.io/pyftdi/urlscheme.html
device_url = "ftdi://ftdi:2232h/1"

# Target frequency
# Achievable frequency depends on the particular part number, and available clock div settings
frequency = 10e6 

TCK_BIT = 0x01
actual_frequency = f.open_mpsse_from_url(device_url, initial=0xFF, direction=TCK_BIT, frequency=frequency)
f.write_data(array('B', (Ftdi.DISABLE_CLK_3PHASE, Ftdi.DISABLE_CLK_ADAPTIVE)))
f.write_data(array('B', (Ftdi.CLK_WAIT_ON_LOW,)))

print("Achieved frequency is %f" % actual_frequency)