AnsweredAssumed Answered

HMC7044 PLL1 stays in reset

Question asked by Lennart_MLE on Jul 24, 2018
Latest reply on Aug 2, 2018 by rgetz

Hi there,


we no configured the structs of the HMC7044 driver but for some reason I can't see any output. So far it looks like the driver is calculating reasonable values from the settings but if I read the status readback registers I see the PLL1 staying in reset. 


Here's the output: 
Alarm Readback Reg 0x007B: 0x00
Alarm Readback Reg 0x007C: 0x00
Alarm Readback Reg 0x007D: 0x02
Alarm Readback Reg 0x007E: 0x00
Alarm Readback Reg 0x007F: 0x00
PLL1 Status Reg 0x0082: 0x00
PLL1 Status Reg 0x0083: 0x40
PLL1 Status Reg 0x0084: 0x3F
PLL1 Status Reg 0x0085:  0x03
PLL2 Status Reg 0x008C: 0x10
PLL2 Status Reg 0x008D: 0xFF
PLL2 Status Reg 0x008E: 0x1F
PLL2 Status Reg 0x008F: 0x00
Sysref Status Reg 0x0091: 0x1A


Any chance you guys have an idea what could cause this? If the input reference is not good enough I'd expect the PLL1 not locking to the clock but it doesn't really seam to do anything?! Does it need a sync? From my understanding the sync is only required to synchronize several HMC7044 devices, which we don't have?!

Any hints would be highly appreciated.