class SpiRfda2125Test:
"""Basic test for a RFDA2125 Digital Controlled Variable Gain Amplifier
selected as CS2,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
self._port = None
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi:///1')
debug = to_bool(environ.get('FTDI_DEBUG', 'off'))
self._spi.configure(url, debug=debug)
self._port = self._spi.get_port(2, freq=1E6, mode=0)
def change_attenuation(self, value):
if not 0.0 <= value <= 31.5:
print('Out-of-bound attenuation', file=stderr)
intval = 63 - int(value * 2)
self._port.write(bytes([intval]), 1)
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class EpdFtdiPort:
"""
"""
DC_PIN = 1 << 5
RESET_PIN = 1 << 6
BUSY_PIN = 1 << 7
I_PINS = BUSY_PIN
O_PINS = DC_PIN | RESET_PIN
IO_PINS = I_PINS | O_PINS
def __init__(self, debug=False):
self._debug = debug
self._spi = SpiController(cs_count=2)
self._spi_port = None
self._io_port = None
self._io = 0
def open(self, url=None):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', url or 'ftdi:///1')
self._spi.configure(url, debug=self._debug)
self._spi_port = self._spi.get_port(0, freq=10E6, mode=0)
self._io_port = self._spi.get_gpio()
self._io_port.set_direction(self.IO_PINS, self.O_PINS)
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
def reset(self):
self._io = self.RESET_PIN
self._io_port.write(self._io)
sleep(0.2)
self._io = 0
self._io_port.write(self._io)
sleep(0.2)
self._io = self.RESET_PIN
self._io_port.write(self._io)
sleep(0.2)
def write_command(self, cmd):
if isinstance(cmd, int):
data = bytes([cmd])
self._io &= ~self.DC_PIN
self._io_port.write(self._io)
self._spi_port.write(data)
def write_data(self, data):
if isinstance(data, int):
data = bytes([data])
self._io |= self.DC_PIN
self._io_port.write(self._io)
self._spi_port.write(data)
def wait_ready(self):
start = now()
while self._io_port.read() & self.BUSY_PIN:
sleep(0.05)
return now() - start
class SpiCsForceTestCase(unittest.TestCase):
"""Basic test for exercing direct /CS control.
It requires a scope or a digital analyzer to validate the signal
waveforms.
"""
@classmethod
def setUpClass(cls):
cls.url = environ.get('FTDI_DEVICE', 'ftdi:///1')
cls.debug = to_bool(environ.get('FTDI_DEBUG', 'off'))
def setUp(self):
self._spi = SpiController(cs_count=1)
self._spi.configure(self.url, debug=self.debug)
self._port = self._spi.get_port(0, freq=1E6, mode=0)
def tearDown(self):
"""Close the SPI connection"""
self._spi.terminate()
def test_cs_default_pulse(self):
for _ in range(5):
self._port.force_select()
def test_cs_long_pulse(self):
for _ in range(5):
self._port.force_select(cs_hold=200)
def test_cs_manual_pulse(self):
for _ in range(5):
self._port.force_select(level=False)
self._port.force_select(level=True)
# beware that random USB bus access does not allow to create
# precise delays. This is only the shorter bound, longer one is
# not defined
sleep(100e-6)
def test_cs_pulse_write(self):
self._port.force_select()
self._port.write([0x00, 0x01, 0x02])
def test_cs_default_pulse_rev_clock(self):
if not self._spi.is_inverted_cpha_supported:
self.skipTest('FTDI does not support mode 3')
self._port.set_mode(3)
for _ in range(5):
self._port.force_select()
class SpiAccelTest(object):
"""Basic test for an ADXL345 device selected as CS1,
SPI mode 3
"""
def __init__(self):
self._spi = SpiController()
def open(self):
"""Open an I2c connection to a slave"""
self._spi.configure('ftdi://ftdi:2232h/1')
def read_device_id(self):
port = self._spi.get_port(1, freq=6E6, mode=3)
device_id = port.exchange([0x00], 1).tobytes()
hex_device_id = hexlify(device_id).decode()
print('DEVICE ID:', hex_device_id)
return hex_device_id
def close(self):
"""Close the I2C connection"""
self._spi.terminate()
class SpiDataFlashTest(object):
"""Basic test for a MX25L1606E data flash device selected as CS0,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController()
def open(self):
"""Open an I2c connection to a slave"""
self._spi.configure('ftdi://ftdi:2232h/1')
def read_jedec_id(self):
port = self._spi.get_port(0, freq=3E6, mode=0)
jedec_id = port.exchange([0x9f], 3).tobytes()
hex_jedec_id = hexlify(jedec_id).decode()
print('JEDEC ID:', hex_jedec_id)
return hex_jedec_id
def close(self):
"""Close the I2C connection"""
self._spi.terminate()
class SpiRfda2125Test(object):
"""Basic test for a RFDA2125 Digital Controlled Variable Gain Amplifier
selected as CS2,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController()
def open(self):
"""Open an I2c connection to a slave"""
self._spi.configure('ftdi://ftdi:2232h/1')
self._port = self._spi.get_port(2, freq=1E6, mode=0)
def change_attenuation(self, value):
if not (0.0 <= value <= 31.5):
print('Out-of-bound attenuation', file=stderr)
intval = 63 - int(value * 2)
self._port.write(bytes([intval]), 1)
def close(self):
"""Close the I2C connection"""
self._spi.terminate()
class SpiAccelTest:
"""Basic test for an ADXL345 device selected as CS1,
SPI mode 3
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi:///1')
debug = to_bool(environ.get('FTDI_DEBUG', 'off'))
self._spi.configure(url, debug=debug)
def read_device_id(self):
port = self._spi.get_port(1, freq=6E6, mode=3)
device_id = port.exchange([0x00], 1)
hex_device_id = hexlify(device_id).decode()
print('DEVICE ID:', hex_device_id)
return hex_device_id
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SpiDataFlashTest:
"""Basic test for a MX25L1606E data flash device selected as CS0,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi:///1')
debug = to_bool(environ.get('FTDI_DEBUG', 'off'))
self._spi.configure(url, debug=debug)
def read_jedec_id(self):
port = self._spi.get_port(0, freq=3E6, mode=0)
jedec_id = port.exchange([0x9f], 3)
hex_jedec_id = hexlify(jedec_id).decode()
print('JEDEC ID:', hex_jedec_id)
return hex_jedec_id
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SpiDataFlashTest(object):
"""Basic test for a MX25L1606E data flash device selected as CS0,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:2232h/1')
self._spi.configure(url)
def read_jedec_id(self):
port = self._spi.get_port(0, freq=3E6, mode=0)
jedec_id = port.exchange([0x9f], 3).tobytes()
hex_jedec_id = hexlify(jedec_id).decode()
print('JEDEC ID:', hex_jedec_id)
return hex_jedec_id
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SpiAccelTest(object):
"""Basic test for an ADXL345 device selected as CS1,
SPI mode 3
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:2232h/1')
self._spi.configure(url)
def read_device_id(self):
port = self._spi.get_port(1, freq=6E6, mode=3)
device_id = port.exchange([0x00], 1).tobytes()
hex_device_id = hexlify(device_id).decode()
print('DEVICE ID:', hex_device_id)
return hex_device_id
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SpiRfda2125Test(object):
"""Basic test for a RFDA2125 Digital Controlled Variable Gain Amplifier
selected as CS2,
SPI mode 0
"""
def __init__(self):
self._spi = SpiController(cs_count=3)
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:2232h/1')
self._spi.configure(url)
self._port = self._spi.get_port(2, freq=1E6, mode=0)
def change_attenuation(self, value):
if not (0.0 <= value <= 31.5):
print('Out-of-bound attenuation', file=stderr)
intval = 63-int(value*2)
self._port.write(bytes([intval]), 1)
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SpiGpioTestCase(unittest.TestCase):
"""Basic test for GPIO access w/ SPI mode
It expects the following I/O setup:
AD4 connected t0 AC0
AD5 connected t0 AC1
AD6 connected t0 AC2
AD7 connected t0 AC3
"""
# AD0: SCLK, AD1: MOSI, AD2: MISO, AD3: /CS
AD_OFFSET = 4
AC_OFFSET = 8
PIN_COUNT = 4
def setUp(self):
self._spi = SpiController(cs_count=1)
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:2232h/1')
self._spi.configure(url)
self._port = self._spi.get_port(0, freq=1E6, mode=0)
self._io = self._spi.get_gpio()
def tearDown(self):
"""Close the SPI connection"""
self._spi.terminate()
def test_ac_to_ad(self):
ad_pins = ((1 << self.PIN_COUNT) - 1) << self.AD_OFFSET # input
ac_pins = ((1 << self.PIN_COUNT) - 1) << self.AC_OFFSET # output
io_pins = ad_pins | ac_pins
def ac_to_ad(ac_output):
ac_output &= ac_pins
ac_output >>= self.AC_OFFSET - self.AD_OFFSET
return ac_output & ad_pins
self._io.set_direction(io_pins, ac_pins)
for ac in range(1 << self.PIN_COUNT):
ac_out = ac << self.AC_OFFSET
ad_in = ac_to_ad(ac_out)
self._io.write(ac_out)
# random SPI exchange to ensure SPI does not change GPIO
self._port.exchange([0x00, 0xff], 2)
rd = self._io.read()
self.assertEqual(rd, ad_in)
self.assertRaises(SpiIOError, self._io.write, ad_pins)
def test_ad_to_ac(self):
ad_pins = ((1 << self.PIN_COUNT) - 1) << self.AD_OFFSET # output
ac_pins = ((1 << self.PIN_COUNT) - 1) << self.AC_OFFSET # input
io_pins = ad_pins | ac_pins
def ad_to_ac(ad_output):
ad_output &= ad_pins
ad_output <<= self.AC_OFFSET - self.AD_OFFSET
return ad_output & ac_pins
self._io.set_direction(io_pins, ad_pins)
for ad in range(1 << self.PIN_COUNT):
ad_out = ad << self.AD_OFFSET
ac_in = ad_to_ac(ad_out)
self._io.write(ad_out)
# random SPI exchange to ensure SPI does not change GPIO
self._port.exchange([0x00, 0xff], 2)
rd = self._io.read()
self.assertEqual(rd, ac_in)
self.assertRaises(SpiIOError, self._io.write, ac_pins)
class SpiData93LC56BTest(object):
"""Basic class for a Microchip 93LC56B data flash device selected as CS0,
SPI mode 0, Active High polarity for CS and Bi-directional data.
Test setup: UM232H connected to the EEPROM on a FT4232H-56Q
Mini Module. The FT4232H is forced into reset by connecting the
RT# pin (CN2-8) to GND (CN2-6). Then make the following
connections between the boards:
UM232H FT4232H-56Q
====== ===========
GND - GND
D0 (CN2-1) - ECL (CN3-6)
D1 (CN2-2) - EDA (CN3-7)
D2 (CN2-3) - EDA (CN3-7)
D3 (CN2-4) - ECS (CN3-5)
NOTE: D1 & D2 are indeed both tied to the same EDA pin.
"""
def __init__(self):
self._spi = SpiController(cs_count=1, cs_pol=0)
self._freq = 1E6
self._mode = 0
self._bidir = True
# Maximum number of read cycles to wait while looking for the
# Ready status after each write
self._write_timeout_cnt = 25
# According to the datasheet, the maximum write time is 6 ms
self._Twc = 0.006
# The opcodes are a full byte to make it easy to use with the
# byte interface of SpiController. These opcodes also include
# the start bit (SB), which is simply the left-most '1'
# bit. The actual 2-bit opcode (OC) follows this start bit.
#
# The instructions ERAL, EWDS, EWEN and WRAL require a special
# address byte to complete the opcode. So they are 2 element
# lists whereas the others are single element lists.
self._SBOC_erase = [0x07]
self._SBOC_eral = [0x04, 0x80] # requires EEPROM Vcc >= 4.5V
self._SBOC_ewds = [0x04, 0x00]
self._SBOC_ewen = [0x04, 0xc0]
self._SBOC_read = [0x06]
self._SBOC_write = [0x05]
self._SBOC_wral = [0x04, 0x40] # requires EEPROM Vcc >= 4.5V
def open(self):
"""Open an SPI connection to a slave"""
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:232h/1')
self._spi.configure(url)
def read_word(self, addr):
# NOTE: Using SPI Mode 0. This really should have the FTDI
# clock the read bits in on the rising edge, at least based on
# my understanding of SPI. However, spi.py reads the bits on
# the falling edge of the clock. For the 93LC56B, this is
# exactly what we want. However, if spi.py ever gets changed,
# will need to do writes and reads seperately with reads in
# SPI Mode 1.
port = self._spi.get_port(0,
freq=self._freq,
mode=self._mode,
bidir=self._bidir)
# byteswap() is to handle little endian data
word = port.exchange(self._SBOC_read + [(addr & 0xFF)], 2)
word = word.byteswap().tobytes()
return word
def read_all(self, readlen):
# NOTE: Using SPI Mode 0. This really should have the FTDI
# clock the read bits in on the rising edge, at least base don
# my understanding of SPI. However, spi.py reads the bits on
# the falling edge of the clock. For the 93LC56B, this is
# exactly what we want. However, if spi.py ever gets changed,
# will need to do writes and reads seperately with reads in
# SPI Mode 1.
port = self._spi.get_port(0,
freq=self._freq,
mode=self._mode,
bidir=self._bidir)
# readlen is byte len but extend it to the nearest 16-bit
# boundary.
readlen = ((readlen + 1) // 2) * 2
data = port.exchange(self._SBOC_read + [0x00], readlen)
# byte swap to handle data in little endian (from:
# https://stackoverflow.com/questions/36096292/
# efficient-way-to-swap-bytes-in-python)
data[0::2], data[1::2] = data[1::2], data[0::2]
#print('DATA: ', data)
#words = spack('H'*(len(data)//2), data)
return data.tobytes()
def write_word(self, addr, word):
port = self._spi.get_port(0,
freq=self._freq,
mode=self._mode,
bidir=self._bidir)
# Must first enable Erase/Write
port.exchange(self._SBOC_ewen)
# Send the word, LSB first (little endian)
port.exchange(self._SBOC_write +
[(addr & 0xFF), word & 0x0000ff, (word & 0x00ff00) >> 8])
# Wait the write time
sleep(self._Twc)
# send a stop condition if sent at least 1 read with stop
# False. Data is thrown away.
status = port.read(1)
print('Status: {}'.format(status))
# Check the last bit of the last byte to make sure it is high
# for Ready
if ((status[-1] & 0x01) == 0x00):
raise SpiIOError('ERROR: SPI Write never completed!')
# Now disable Erase/Write since done with this write
port.exchange(self._SBOC_ewds)
# Write multiple bytes starting at byte address, addr. Length of
# data must be a multiple of 2 since the EEPROM is 16-bits. So
# extend data by 1 byte if this is not the case.
def write(self, addr, data):
if not isinstance(data, bytes):
data = data.tobytes()
# If addr is odd, raise an exception since it must be even
if (addr & 0x01):
err = "write addr must be even - the EEPROM is a 16-bit device"
raise SpiIOError(err)
wd_addr = (addr >> 1) # convert to word address
# if the byte data is an odd number of bytes, force it to be
# on 16-bit divisions
if (len(data) & 0x01):
err = "data length must be even - the EEPROM is a 16-bit device"
raise SpiIOError(err)
port = self._spi.get_port(0,
freq=self._freq,
mode=self._mode,
bidir=self._bidir)
# Must first enable Erase/Write
port.exchange(self._SBOC_ewen)
for idx in range(0, len(data), 2):
# Send the word, MSB first
port.exchange(self._SBOC_write +
[(wd_addr & 0xFF), data[idx + 1], data[idx]])
# Wait the write time
sleep(self._Twc)
# send a stop condition if sent at least 1 read with stop
# False. Data is thrown away.
status = port.read(1)
# Check the last bit of the last byte to make sure it is
# high for Ready
if ((status[-1] & 0x01) == 0x00):
print('ERROR: Last write never completed! Aborting!')
break
# increment to the next word address
wd_addr += 1
# Now disable Erase/Write since done with this write
port.exchange(self._SBOC_ewds)
def close(self):
"""Close the SPI connection"""
self._spi.terminate()
class SPIDriver:
"""
Class that contains the driver for the FTDI SPI + GPIO.
"""
def __init__(self):
self.ctrl = None
self.slave = None
print('Starting driver ...')
self.begin()
def begin(self):
try:
self.ctrl = SpiController(cs_count=1)
s = 'ftdi://0x0403:0x6011/1'
self.ctrl.configure(s)
self.slave = self.ctrl.get_port(cs=0, freq=6E6, mode=3)
self.slave.set_frequency(8000000)
self.gpio = self.ctrl.get_gpio()
self.gpio.set_direction(
0x10, 0x10) # direction for the fet controller is OUTPUT (1)
self.gpio.write(0x10)
time.sleep(0.1)
# to account for using separate ports for power and comms:
self.backup_ctrl = SpiController(cs_count=1)
self.backup_gpio = None
if not s == 'ftdi://0x0403:0x6011/1':
backup_s = 'ftdi://0x0403:0x6011/1'
self.backup_ctrl.configure(backup_s)
self.backup_gpio = self.backup_ctrl.get_gpio()
self.backup_gpio.set_direction(0x10, 0x10)
self.backup_gpio.write(0x10)
time.sleep(1)
except Exception as err:
print('Error in initialising the FTDI driver ...:', err)
def write_data_out(self, buffer):
if not isinstance(buffer, bytes):
raise Exception # TODO define exception
try:
self.slave.write(buffer)
return True
except Exception as err:
#TODO convert to Logging
print('Error in writing data out to FTDI SPI...:', err)
return False
def set_power_on(self):
self.gpio.write(0x10)
if self.backup_gpio is not None:
self.backup_gpio.write(0x10)
def set_power_off(self):
self.gpio.write(0x00)
if self.backup_gpio is not None:
self.backup_gpio.write(0x00)
def terminate(self):
self.ctrl.terminate()
print('terminated')
##Rx
#write_one(0x0f , 0x00) #REG_0F_FIFO_RX_BASE_ADDR --> p.35. tte la memory FIFO assignee au Rx
#write_one(0x12 , 0xff) #REG_12_IRQ_FLAGS clear ses flags
#write_one(0x01 , 0x05) #mode RxContinuous
#while True:
#print("IRQ FLAGS:", format(read_one(0x12), '#010b')) #REG_12_IRQ_FLAGS
# if(read_one(0x12) & 0x40): # RX_DONE flag is up!
# lecture_rx()
# write_one(0x12 , 0xff) #REG_12_IRQ_FLAGS clear ses flags
# sleep(1)
###Tx
payload = bytearray(b'9105dc77b881dbcca8b')
write_one(0x0e,
0x00) #REG_0E_FIFO_TX_BASE_ADDR cf.p35 (si Rx en même temps???)
write_one(0x0d, 0x00) #REG_0D_FIFO_ADDR_PTR
slave.exchange(
b'\x80' + payload
) #premier byte = FIFO_ADDR8_PTR (0x00) oré avec write (0x80) cf p.80
write_one(0x22, len(payload)) #REG_22_PAYLOAD_LENGTH
write_one(0x01, 0x03) #mode Tx
sleep(1) #attendre que le Tx se fasse
write_one(
0x01, 0x01
) #revenir en mode STDBY (0x01) (En Tx dapres datasheet p.36 devrait se faire seul)
#print(hex(read_one(0x06)))
#print(format(read_one(0x06), '#010b'))
spi.terminate()
class SpiUnalignedTestCase(unittest.TestCase):
"""Basic test for SPI with non 8-bit multiple transfer
It expects the following I/O setup:
MOSI (AD1) connected to MISO (AD2)
"""
@classmethod
def setUpClass(cls):
cls.url = environ.get('FTDI_DEVICE', 'ftdi:///1')
cls.debug = to_bool(environ.get('FTDI_DEBUG', 'off'))
def setUp(self):
self._spi = SpiController(cs_count=1)
self._spi.configure(self.url, debug=self.debug)
self._port = self._spi.get_port(0, freq=1E6, mode=0)
def tearDown(self):
"""Close the SPI connection"""
self._spi.terminate()
def test_invalid_write(self):
buf = b'\xff\xff'
self.assertRaises(ValueError, self._port.write, buf, droptail=8)
def test_bit_write(self):
buf = b'\x0f'
for loop in range(7):
self._port.write(buf, droptail=loop + 1)
def test_bytebit_write(self):
buf = b'\xff\xff\x0f'
for loop in range(7):
self._port.write(buf, droptail=loop + 1)
def test_invalid_read(self):
self.assertRaises(ValueError, self._port.read, 1, droptail=8)
self.assertRaises(ValueError, self._port.read, 2, droptail=8)
def test_bit_read(self):
# make MOSI stay to low level, so MISO samples 0
self._port.write([0x00])
for loop in range(7):
data = self._port.read(1, droptail=loop + 1)
self.assertEqual(len(data), 1)
# make MOSI stay to high level, so MISO samples 1
self._port.write([0x01])
for loop in range(7):
data = self._port.read(1, droptail=loop + 1)
self.assertEqual(len(data), 1)
def test_bytebit_read(self):
self._port.write([0x00])
for loop in range(7):
data = self._port.read(3, droptail=loop + 1)
self.assertEqual(len(data), 3)
self.assertEqual(data[-1], 0)
self._port.write([0x01])
for loop in range(7):
data = self._port.read(3, droptail=loop + 1)
self.assertEqual(len(data), 3)
def test_invalid_duplex(self):
buf = b'\xff\xff'
self.assertRaises(ValueError,
self._port.exchange,
buf,
duplex=False,
droptail=8)
self.assertRaises(ValueError,
self._port.exchange,
buf,
duplex=False,
droptail=8)
self.assertRaises(ValueError,
self._port.exchange,
buf,
duplex=True,
droptail=8)
self.assertRaises(ValueError,
self._port.exchange,
buf,
duplex=True,
droptail=8)
def test_bit_duplex(self):
buf = b'\xcf'
for loop in range(7):
data = self._port.exchange(buf, duplex=True, droptail=loop + 1)
self.assertEqual(len(data), 1)
exp = buf[0] & ~((1 << (loop + 1)) - 1)
# print(f'{data[0]:08b} {exp:08b}')
self.assertEqual(data[0], exp)
def test_bytebit_duplex(self):
buf = b'\xff\xcf'
for loop in range(7):
data = self._port.exchange(buf, duplex=True, droptail=loop + 1)
self.assertEqual(len(data), 2)
exp = buf[-1] & ~((1 << (loop + 1)) - 1)
# print(f'{data[-1]:08b} {exp:08b}')
self.assertEqual(data[0], 0xFF)
self.assertEqual(data[-1], exp)
class FtdiDevice:
"""FTDI FT2232H SPI master to access FPGA Control/Status Registers (CSR)
plus some GPIO control.
SPI parameters:
- FTDI channel B:
* BDBUS0 - SCLK
* BDBUS1 - MOSI
* BDBUS2 - MISO
* BDBUS3 - CSn
- slave;
- mode 0 only;
- most significant bit transmitted first;
- byte order from high to low;
- SCK frequency must at least 8 lower than system frequency.
There are 2 types of SPI transactions:
- incremental burst -- address increments internally after every data (array)
- fixed burst -- one adreess, multiple data (FIFO)
Transaction is done with 8-bit address and 16 bit data words.
Transaction format:
- control word (3 bytes):
* bit 23 -- write (1) or read (0)
* bit 22 -- burst incremental (1) or fixed (0)
* bit 21 .. 8 -- 14 bit length (0 - 1 data word, 1 - 2 data words, etc)
* bits 7 .. 0 -- 8 bit address
- data word (2 bytes) 1 .. N:
* bits 15 .. 0 -- data to be written or readen
GPIO parameters:
- ADBUS7 - output - active low reset for FPGA configuration (ICE_RESET)
- BDBUS7 - output - active high reset for FPGA logic (ICE_RESET_FT)
"""
GPIO_RESET_LOGIC_POS = 7
GPIO_RESET_CONFIG_POS = 7
def __init__(self, ftdi_url, spi_freq=1E6):
"""Configure the FTDI interface.
Keyword arguments:
ftdi_url -- device url, which can be obtained by Ftdi.show_devices()
freq -- SPI frequency up to 8E6 (for FPGA running on 64 MHz)
"""
# Configure SPI master
self._spi_ctrl = SpiController()
self._spi_ctrl.configure(ftdi_url + '2') # second port - channel B
self._spi_port = self._spi_ctrl.get_port(cs=0, freq=spi_freq, mode=0)
# Configure FPGA logic reset (ICE_RESET_FT)
self._spi_gpio = self._spi_ctrl.get_gpio()
self._spi_gpio.set_direction(1 << self.GPIO_RESET_LOGIC_POS,
1 << self.GPIO_RESET_LOGIC_POS)
self._spi_gpio.write(0)
# Configure FPGA configuration reset (ICE_RESET)
self._gpio_ctrl = GpioAsyncController()
self._gpio_ctrl.configure(
ftdi_url + '1', # first port - channel A
direction=(1 << self.GPIO_RESET_CONFIG_POS),
frequency=1e6,
initial=(1 << self.GPIO_RESET_CONFIG_POS))
self._gpio_ctrl.write(1 << self.GPIO_RESET_CONFIG_POS)
def _int_to_bytes(self, i, length=2):
"""Convert integer to bytes"""
return int.to_bytes(i, length=length, byteorder='big', signed=False)
def _words_to_bytes(self, words_list):
"""Convert list with 16 bit words to bytes"""
bytes_str_list = [self._int_to_bytes(w, length=2) for w in words_list]
return b''.join(bytes_str_list) # concatenate all strings
def _bytes_to_words(self, bytes_str):
"""Convert bytes string to list with 16 bit words"""
return [
int.from_bytes(bytes_str[b * 2:b * 2 + 2],
byteorder='big',
signed=False) for b in range(len(bytes_str) // 2)
]
def _prepare_ctrl_word(self, addr, len, burst, wr):
"""Prepare control word for exchange.
Keyword arguments:
addr -- 8 bit address
len -- number of 16 bit data words to write/read (2^14 max)
burst -- 'fixed' address the same for every data, 'incr' - address + 1 for every next data word
wr -- 1 for write operation, 0 - for read
"""
ctrl_word = 0
ctrl_word |= (wr << 23)
ctrl_word |= ((burst == 'incr') << 22)
ctrl_word |= (((len - 1) & 0x3FFF) << 8)
ctrl_word |= ((addr & 0xFF) << 0)
return ctrl_word
def spi_read(self, addr, len=1, burst='fixed'):
"""Read data from address via SPI.
Keyword arguments:
addr -- 8 bit address
len -- number of 16 bit data words to write/read (2^14 max)
burst -- 'fixed' address the same for every data, 'incr' - address + 1 for every next data word
Return:
list of size 'len' with 16 bit data words
"""
ctrl_word = self._prepare_ctrl_word(addr, len, burst, wr=0)
rbytes = self._spi_port.exchange(self._int_to_bytes(ctrl_word, 3),
len * 2)
return self._bytes_to_words(rbytes)
def spi_write(self, addr, data, burst='fixed'):
"""Write data to address via SPI.
Keyword arguments:
addr -- 8 bit address
data -- list with 16 bit data words to write (list length 2^14 max)
burst -- 'fixed' address the same for every data, 'incr' - address + 1 for every next data word
"""
ctrl_word = self._prepare_ctrl_word(addr, len(data), burst, wr=1)
wbytes = self._int_to_bytes(ctrl_word, 3) + self._words_to_bytes(data)
self._spi_port.exchange(wbytes)
def reset_logic_on(self):
"""Activate reset pin ICE_RESET_FT"""
self._spi_gpio.write((1 << self.GPIO_RESET_LOGIC_POS)
| self._spi_gpio.read())
def reset_logic_off(self):
"""Deactivate reset pin ICE_RESET_FT"""
self._spi_gpio.write(~(1 << self.GPIO_RESET_LOGIC_POS)
& self._spi_gpio.read())
def reset_config_on(self):
"""Activate reset pin ICE_RESET"""
self._gpio_ctrl.write(~(1 << self.GPIO_RESET_CONFIG_POS)
& self._gpio_ctrl.read())
def reset_config_off(self):
"""Deactivate reset pin ICE_RESET"""
self._gpio_ctrl.write((1 << self.GPIO_RESET_LOGIC_POS)
| self._gpio_ctrl.read())
def close_connection(self):
"""Close FTDI interface"""
self._spi_ctrl.terminate()
self._gpio_ctrl.close()
class SpiGpioTestCase(unittest.TestCase):
"""Basic test for GPIO access w/ SPI mode
It expects the following I/O setup:
AD4 connected t0 AC0
AD5 connected t0 AC1
AD6 connected t0 AC2
AD7 connected t0 AC3
"""
# AD0: SCLK, AD1: MOSI, AD2: MISO, AD3: /CS
AD_OFFSET = 4
AC_OFFSET = 8
PIN_COUNT = 4
def setUp(self):
self._spi = SpiController(cs_count=1)
url = environ.get('FTDI_DEVICE', 'ftdi://ftdi:2232h/1')
self._spi.configure(url)
self._port = self._spi.get_port(0, freq=1E6, mode=0)
self._io = self._spi.get_gpio()
def tearDown(self):
"""Close the SPI connection"""
self._spi.terminate()
def test_ac_to_ad(self):
ad_pins = ((1 << self.PIN_COUNT) - 1) << self.AD_OFFSET # input
ac_pins = ((1 << self.PIN_COUNT) - 1) << self.AC_OFFSET # output
io_pins = ad_pins | ac_pins
def ac_to_ad(ac_output):
ac_output &= ac_pins
ac_output >>= self.AC_OFFSET - self.AD_OFFSET
return ac_output & ad_pins
self._io.set_direction(io_pins, ac_pins)
for ac in range(1 << self.PIN_COUNT):
ac_out = ac << self.AC_OFFSET
ad_in = ac_to_ad(ac_out)
self._io.write(ac_out)
# random SPI exchange to ensure SPI does not change GPIO
self._port.exchange([0x00, 0xff], 2)
rd = self._io.read()
self.assertEqual(rd, ad_in)
self.assertRaises(SpiIOError, self._io.write, ad_pins)
def test_ad_to_ac(self):
ad_pins = ((1 << self.PIN_COUNT) - 1) << self.AD_OFFSET # output
ac_pins = ((1 << self.PIN_COUNT) - 1) << self.AC_OFFSET # input
io_pins = ad_pins | ac_pins
def ad_to_ac(ad_output):
ad_output &= ad_pins
ad_output <<= self.AC_OFFSET - self.AD_OFFSET
return ad_output & ac_pins
self._io.set_direction(io_pins, ad_pins)
for ad in range(1 << self.PIN_COUNT):
ad_out = ad << self.AD_OFFSET
ac_in = ad_to_ac(ad_out)
self._io.write(ad_out)
# random SPI exchange to ensure SPI does not change GPIO
self._port.exchange([0x00, 0xff], 2)
rd = self._io.read()
self.assertEqual(rd, ac_in)
self.assertRaises(SpiIOError, self._io.write, ac_pins)