diff --git a/fast-servo/pyfastservo/adc.py b/fast-servo/pyfastservo/adc.py
index e04a47e..9cbe137 100644
--- a/fast-servo/pyfastservo/adc.py
+++ b/fast-servo/pyfastservo/adc.py
@@ -17,8 +17,6 @@
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
-import mmap
-import os
import spidev
from pyfastservo.common import (
@@ -33,6 +31,8 @@ from pyfastservo.common import (
AUX_ADC_ADDR,
MAP_MASK,
PAGESIZE,
+ write_to_memory,
+ read_from_memory
)
# /dev/spidev1.0 <=> spidev.
@@ -44,276 +44,118 @@ AUX_ADC_PORT_A = 2
AUX_ADC_PORT_B = 3
-def main_adc_config(test_pattern):
+def spi_write(spi, address, value):
+ spi.xfer2([address, value])
+
+def spi_read(spi, address):
+ rx_buffer = spi.xfer2([0x80 | address, 0x00])
+ return rx_buffer[1]
+
+def main_adc_config(spi, test_pattern):
high_word = (test_pattern & 0xFF00) >> 8
low_word = test_pattern & 0xFF
- spi = spidev.SpiDev()
+ spi_write(spi, 0x00, 0x80) # reset
+ spi_write(spi, 0x01, 0x20) # REGISTER A1: set to Two's complement Data Format
+ spi_write(spi, 0x02, 0x15) # REGISTER A2: set to LVDS output, set 4 data lanes and turn on test mode
+ spi_write(spi, 0x03, high_word) # REGISTER A3: test pattern high word
+ spi_write(spi, 0x04, low_word) # REGISTER A4: test pattern low word
- try:
- spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
- spi.max_speed_hz = 50000
- spi.mode = 0b00 # CPOL = 0 CPHA = 0
- spi.cshigh = False
- # spi.read0 = False
+def main_adc_test_mode(spi, enable):
+ reg_contents = 0x15 if enable else 0x11 # set to LVDS output, set 4 data lanes and turn on or off test mode
+ spi_write(spi, 0x02, reg_contents)
- spi_buffer = [0x00, 0x80] # reset
- rx_buffer = [0x00, 0x00]
+def verify_adc_registers(spi, reg_to_check):
+ for register, expected_value in reg_to_check.items():
+ value = spi_read(spi, register)
+ print(f"Spi readback register 0x{register:02x}: 0x{value:02x}")
+ if value != expected_value:
+ print(f"Different value read than sent in reg 0x{register:02x}")
- spi.xfer2(spi_buffer)
-
- # REGISTER A1
- spi_buffer = [0x01, 0x20] # set to Two's complement Data Format
- spi.xfer2(spi_buffer)
-
- # read values back
- spi_buffer = [0x81, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"Spi readback register 0x01: 0x{rx_buffer[1]:02x}")
- if rx_buffer[1] != 0x20:
- print("Different value read than sent in reg 0x02")
-
- # REGISTER A2
- spi_buffer = [
- 0x02,
- 0x15,
- ] # set to LVDS output, set 4 data lanes and turn on test mode
- spi.xfer2(spi_buffer)
-
- # read values back
- spi_buffer = [0x82, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"Spi readback register 0x02: 0x{rx_buffer[1]:02x}")
- if rx_buffer[1] != 0x15:
- print("Different value read than sent in reg 0x02")
-
- # REGISTER A3
- # test pattern high word
- spi_buffer = [0x03, high_word]
- spi.xfer2(spi_buffer)
-
- # read balues back
- spi_buffer = [0x83, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"Spi readback register 0x03: 0x{rx_buffer[1]:02x}")
- if rx_buffer[1] != high_word:
- print("Different value read than sent in reg 0x03")
-
- # REGISTER A4
- # test pattern low word
- spi_buffer = [0x04, low_word]
- spi.xfer2(spi_buffer)
-
- # read balues back
- spi_buffer = [0x84, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"Spi readback register 0x04: 0x{rx_buffer[1]:02x}")
- if rx_buffer[1] != low_word:
- print("Different value read than sent in reg 0x04")
- finally:
- spi.close()
-
-
-def main_adc_test_mode(enable):
- spi = spidev.SpiDev()
-
- try:
- spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
- spi.max_speed_hz = 50000
- spi.mode = 0b00 # CPOL = 0 CPHA = 0
- spi.cshigh = False
- # spi.read0 = True
-
- reg_contents = (
- 0x15 if enable else 0x11
- ) # set to LVDS output, set 4 data lanes and turn on or off test mode
- spi_buffer = [0x02, reg_contents]
- spi.xfer2(spi_buffer)
-
- # read values back
- spi_buffer = [0x82, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"Spi readback register 0x02: 0x{rx_buffer[1]:02x}")
- if rx_buffer[1] != reg_contents:
- print("Different value read than sent in reg 0x02")
- finally:
- spi.close()
-
-
-def read_from_memory(address, n_bytes):
- assert n_bytes <= 4
- addr = address
-
- try:
- f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
- with mmap.mmap(
- f,
- PAGESIZE,
- mmap.MAP_SHARED,
- mmap.PROT_READ | mmap.PROT_WRITE,
- offset=addr & ~MAP_MASK,
- ) as mem:
- start_addr = addr & MAP_MASK
- stop_addr = start_addr + 4
- # print(f"addr: 0x{addr:x}\tstart_addr: 0x{start_addr}\tstop_addr: 0x{stop_addr}")
- contents = mem[start_addr:stop_addr]
- read_value = list(contents)[:n_bytes]
- # print("Read value: ", read_value)
- finally:
- os.close(f)
-
- return read_value
-
-
-def write_to_memory(address, value):
- value_bytes = value.to_bytes(4, "little")
- addr = address
-
- try:
- f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
- with mmap.mmap(
- f,
- PAGESIZE,
- mmap.MAP_SHARED,
- mmap.PROT_READ | mmap.PROT_WRITE,
- offset=addr & ~MAP_MASK,
- ) as mem:
- start_addr = addr & MAP_MASK
- stop_addr = start_addr + 4
- # print(f"addr: 0x{addr:x}\tstart_addr: 0x{start_addr}\tstop_addr: 0x{stop_addr}")
- mem[start_addr:stop_addr] = value_bytes
- contents = mem[start_addr:stop_addr]
- # print("Read value: ", list(contents), " written value: ", list(value_bytes))
- finally:
- os.close(f)
-
-
-def word_align():
-
- value = 0
- edge_detected = False
- transition = False
- tap_delay = 0
+def read_frame():
+ return read_from_memory(ADC_FRAME_ADDR, 1)[0]
+def perform_bitslip():
for i in range(4):
- current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
+ current_frame = read_frame()
if current_frame != 0x0C:
- print(
- f"Performing bitslip (bitslip iteration: {i}). Reason: current_frame is 0x{current_frame:02x} instead of 0x0C"
- )
+ print(f"Performing bitslip (iteration: {i}). Current frame: 0x{current_frame:02x}")
write_to_memory(ADC_BITSLIP_ADDR, 1)
else:
- print(f"No bitslip required; Currernt frame = 0x{current_frame:02x}")
- break
+ print(f"No bitslip required; Current frame: 0x{current_frame:02x}")
+ return
- current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
- prev_frame = current_frame
-
- for i in range(32):
+def find_edge():
+ prev_frame = read_frame()
+ transition = False
+ for tap_delay in range(32):
write_to_memory(ADC_DELAY_ADDR, tap_delay)
- if edge_detected == 1:
- break
- current_frame = read_from_memory(ADC_FRAME_ADDR, 1)[0]
+ current_frame = read_frame()
- print(f"Tap delay: {tap_delay}")
- print(f"Current frame: 0x{current_frame:02x}")
+ print(f"Tap delay: {tap_delay}, Current frame: 0x{current_frame:02x}")
- if current_frame == prev_frame:
- tap_delay += 1
- elif not transition:
- tap_delay += 1
- transition = True
- elif transition:
- tap_delay = i // 2
- edge_detected = True
+ if current_frame != prev_frame:
+ if not transition:
+ transition = True
+ else:
+ final_delay = (tap_delay // 2) + 2
+ print(f"Edge detected; setting iDelay to: {final_delay}")
+ write_to_memory(ADC_DELAY_ADDR, final_delay)
+ return
prev_frame = current_frame
- if not edge_detected:
- tap_delay = 11 # empirically tested to work best
- write_to_memory(ADC_DELAY_ADDR, tap_delay)
- print(f"No edge detected; setting iDelay to: {tap_delay}")
- if edge_detected:
- write_to_memory(ADC_DELAY_ADDR, tap_delay + 2)
- print(f"Edge detected; setting iDelay to (tap_delay + 2): {tap_delay} + 2")
+ # If no edge detected
+ final_delay = 11
+ print(f"No edge detected; setting iDelay to: {final_delay}")
+ write_to_memory(ADC_DELAY_ADDR, final_delay)
- adc_ch0 = read_from_memory(ADC_CH0_HIGH_ADDR, 4)
- print(f"ADC_CH0: 0x{adc_ch0}")
+def read_adc_channel(high_addr, low_addr):
+ return (read_from_memory(high_addr, 1)[0] << 8) | read_from_memory(low_addr, 1)[0]
- adc_ch0 = (read_from_memory(ADC_CH0_HIGH_ADDR, 1)[0] << 8) | read_from_memory(
- ADC_CH0_LOW_ADDR, 1
- )[0]
- adc_ch1 = (read_from_memory(ADC_CH1_HIGH_ADDR, 1)[0] << 8) | read_from_memory(
- ADC_CH1_LOW_ADDR, 1
- )[0]
+def print_adc_channels():
+ adc_ch0 = read_adc_channel(ADC_CH0_HIGH_ADDR, ADC_CH0_LOW_ADDR)
+ adc_ch1 = read_adc_channel(ADC_CH1_HIGH_ADDR, ADC_CH1_LOW_ADDR)
print(f"Final ADC_CH0: 0x{adc_ch0:04x}")
print(f"Final ADC_CH1: 0x{adc_ch1:04x}")
+def enable_adc_afe(ch1_x10=False, ch2_x10=False):
+ ctrl_value = (ch2_x10 << 1) | ch1_x10
+ write_to_memory(ADC_AFE_CTRL_ADDR, ctrl_value)
+ afe_ctrl = read_from_memory(ADC_AFE_CTRL_ADDR, 1)[0]
+ print(f"ADC_AFE_CTRL: 0x{afe_ctrl:02X}")
+ return afe_ctrl
-def modify_bit(original_value, position, bit_value):
- mask = 1 << position
- return (original_value & ~mask) | (bit_value << position)
-
-
-def adc_aux_config():
- # MSB to LSB
- # | RANGE | ADDR [2:0] | DIFF |
- # DIFF = 0 => configure as single ended (it is negated in gateware)
- # RANGE = 0 => configure as 0-2.5 Vref
- to_write = 0b00000
- write_to_memory(AUX_ADC_ADDR, to_write)
-
-
-def adc_aux_read(port, type, pin):
- # port:
- # 1 - port A
- # 2 - port B
- # type:
- # 0 - single-ended
- # 1 - differential
- # pin:
- # 0b000 - VA1/VB1
- # 0b001 - VA2/VB2
- # 0b010 - VA3/VB3
- # 0b011 - VA4/VB4
-
- assert type in (0, 1)
- assert port in (1, 2)
-
- write_buffer = [0, 0]
- read_buffer = [0, 0]
-
- aux_config_reg = read_from_memory(AUX_ADC_ADDR, 1)[0]
- aux_config = (aux_config_reg & 0b10001) | pin << 1
- write_to_memory(AUX_ADC_ADDR, aux_config)
-
+def configure_ltc2195():
spi = spidev.SpiDev()
try:
- spi.open(1, 3) # AUX ADC 1?
- spi.max_speed_hz = 5000
- spi.mode = 0b00
+ spi.open(MAIN_ADC_BUS, MAIN_ADC_DEVICE)
+ spi.max_speed_hz = 50000
+ spi.mode = 0b00 # CPOL = 0 CPHA = 0
spi.cshigh = False
- read_buffer = spi.xfer2(write_buffer)
- mu_voltage = read_buffer[0] << 8 | read_buffer[1] >> 2
- print(f"MU_voltage: 0x{mu_voltage:04X}")
- print(f"Read_buffer[0]: 0x{read_buffer[0]:02X}")
- print(f"Read_buffer[1]: 0x{read_buffer[1]:02X}")
- return mu_voltage * 2.5 / 4096
+ test_pattern = 0x811F
+ main_adc_config(spi, test_pattern)
+
+ verify_adc_registers(spi, {
+ 0x01: 0x20,
+ 0x02: 0x15,
+ 0x03: (test_pattern & 0xFF00) >> 8,
+ 0x04: test_pattern & 0xFF
+ })
+
+ # Performing Word Align
+ perform_bitslip()
+ find_edge()
+ print_adc_channels()
+
+ main_adc_test_mode(spi, False)
+ verify_adc_registers(spi, {0x02: 0x11}) # Verify test mode is off
+
+ enable_adc_afe()
finally:
spi.close()
-
-def main():
- main_adc_config(0x811F)
- word_align()
-
- main_adc_test_mode(False)
-
- write_to_memory(ADC_AFE_CTRL_ADDR, 0b1100) # {-, -, ch2_X10, ch1_X10}
- print(read_from_memory(ADC_AFE_CTRL_ADDR, 1)[0])
-
-
if __name__ == "__main__":
- main()
\ No newline at end of file
+ configure_ltc2195()
\ No newline at end of file