Special SQ1 Bias Commands

Address Card has a special multiplexing mode, enbl_mux = 3. In this mode, selected SQ1 Bias lines are turned on for an adjustable duration in the begining of a row visit, before the target SQ1 Bias for that row is turned on. The DACS are updated with heater_bias values during the first heater_bias_len clock cycles, and with on_bias values for the remaining clock cycles of a row visit. The following parameters need to be set for this mode:

heater_bias

Upto 41 values that specify the magnitude of the SQ1-bias heating pulse in DAC units (0 to 16,383) during the initial heater_bias_len period of each row visit.

heater_bias_len

a single value that specifies the length of the SQ1-bias heating pulses at the beginning of every new row period. heater_bias_len is measured from the first clock cycle of each new row dwell time. However, it takes 4 clock cycles to apply all the heater biases. This means the heater biases are applied by clock cycle #5.

enbl_mux

set enbl_mux = 3 for this special multiplexing mode.

Note 1: these commands are only available in AC firmware 2.0.9 and 5.0.2.
Note 2: bias_start parameter is not taken into account in this special multiplexing mode.

Here is a timing diagram of SQ1 Bias when enbl_mux = 3