Read FPGA-NSP sync pulse using software

[chongxi]

Now it is possible to read the sync_pulse out of the FPGA using spiketag.fpga.memory_api.read_mem_16

FPGA sync pulse:

[chongxi]

from spiketag.fpga.memory_api import read_mem_16
import time
sync = []
while True:
    sync.append(read_mem_16(0))
    time.sleep(0.01)

After start recording, stop the software sync recording loop and then plot the result:

The second duration is exactly twice length of the first duration.