SIGNALCORE SC5511A Operating & Programming Manual page 16

Communication Interfaces
USB interface is common on the SC5511A, while an alternative interface option is SPI or RS232. As both
the SPI and RS232 utilize the same internal communication device, and thus the same connector pins,
only one option is possible.
SPI Interface
In addition to the 4-wire SPI (CS, SDO, SDI, and SCLK) signal lines, there is also an alternative
serial ready SRDY line. Upon reception of a register command, the device takes time to execute
the command instruction, such as setting a new frequency. While the device is busy, the SRDY
line will go low and returns high upon execution completion. Detailed SPI read and write
operations are discussed in detail in the Serial Peripheral Interface (SPI) section.
USB Interface
The SC5511A has a built-in USB controller configured in client mode. The transfer types
supported by the device are control, interrupt, and bulk. More information on the use of the
USB interface and its software API are provided in the USB Interface section.
Default Startup Mode
The factory power-up state for the device is detailed in Table 4. The default state can be changed to the
current state of either channel programmatically, allowing the user to power up the device in the last
saved state without having to reprogram.
Table 4. Factory default power-up state.
Frequency
Power
RF Output
ALC Mode Closed Loop
Standby
Auto Level
Ref Out Select
Ext Ref Lock
SC5511A User Manual
CH1 CH2
12 GHz 1.5 GHz
0.00 dBm Max
Enabled NA
NA
Disabled Enabled
Enabled NA
10 MHz
Disabled
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