From 515cfa7dfb9d0f5fc9834c05ac86989ffa65c6da Mon Sep 17 00:00:00 2001 From: Marius Weber Date: Fri, 2 Apr 2021 21:05:23 +0100 Subject: [PATCH] Phaser: expose coarse mixer and document need to enable the DAC-mixer. in some use cases a larger tunable range than available via the DUC may be needed. Some use cases may wish to combine the coarse mixer with the DUC to extend the tunable range. Signed-off-by: Marius Weber --- artiq/coredevice/phaser.py | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/artiq/coredevice/phaser.py b/artiq/coredevice/phaser.py index 7d26f238b..13ed4e37a 100644 --- a/artiq/coredevice/phaser.py +++ b/artiq/coredevice/phaser.py @@ -570,6 +570,27 @@ class Phaser: self.dac_write(0x1f, config1f & ~int32(1 << 1)) self.dac_write(0x1f, config1f | (1 << 1)) + @kernel + def set_dac_cmix(self, fs_8_step): + """Set the DAC coarse mixer frequency for both channels + + The selected coarse mixer frequency becomes active without explicit + synchronisation. + + Use of the coarse mixer requires the DAC mixer to be enabled. The mixer + can be configured via the `dac` device_db entries. + + :param fs_8_step: coarse mixer frequency shift in 125 MHz steps. This + should be an integer between -3 and 4 (inclusive). + """ + # values recommended in data-sheet + # 0 1 2 3 4 -3 -2 -1 + vals = [0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0001, 0b1110] + cmix = vals[fs_8_step%8] + config0d = self.dac_read(0x0d) + delay(.1*ms) + self.dac_write(0x0d, (config0d & ~(0b1111 << 12)) | (cmix << 12)) + @kernel def get_dac_alarms(self): """Read the DAC alarm flags. @@ -784,6 +805,9 @@ class PhaserChannel: """Set the NCO frequency. The frequency is only applied after DAC synchronisation. + Use of the NCO requires the DAC mixer to be enabled. The mixer can be + configured via the `dac` device_db entries. + :param ftw: NCO frequency tuning word (32 bit) """ self.phaser.dac_write(0x15 + (self.index << 1), ftw >> 16) @@ -794,6 +818,9 @@ class PhaserChannel: """Set the NCO frequency in SI units. The frequency is only applied after DAC synchronisation. + Use of the NCO requires the DAC mixer to be enabled. The mixer can be + configured via the `dac` device_db entries. + :param frequency: NCO frequency in Hz (passband from -400 MHz to 400 MHz, wrapping around at +- 500 MHz) """