Hi,
I am using Murata ZY type which uses DA14580.
I am wondering if I can boot through development mode and let it download the firmware
via UART without any external oscillator connected to it?
is there any disanvantage?
Thanks
Keywords:
Device:
Hi meriororen,
Please check this posthttp://support.dialog-semiconductor.com/xtal-16mhz-and-32khz-must
The RC16M oscillator is inaccurate i suppose that without it you wouldn't be able to establish a proper connection.
Thanks MT_dialog
Hi MT_Dialog/meriororen,
To meriororen: I am using the Type ZF also, it has a 32.768kHz crystal connected already, so it would *seem* to be necessary. The Murata chip DOES NOT HAVE pins for the 16MHz crystal, therefore a 16MHz crystal *must* be built in to the Murata. However, see my questions to MT_Dialog.
To MT_Dialog: I have a couple questions that maybe you can answer here, for the benefit of everyone else that might need this information.
The question is "when it comes time to design our own PCB using a DA14580, do we NEED TO HAVE A 32.768kHz CRYSTAL CONNECTED TO PINS XTAL32kP and XTAL32kM to establish a proper connection, via UART/SPI to another microcontroller?" The answer/link above are both horribly vague, even more so when we try to extend the answers to include the Murata Type ZF.
1.专门使用DA14580（不是Murata的风味）第142-3页的数据表'DA14580_DS_V3-1'显示了两个不同电源，锂硬币电池和碱性电池的图。在两个图中，它显示了16MHz晶体。所以我们可以推断出来，无论我们使用的电池电压是什么，我们都必须在PCB上有一个16MHz水晶。这是真的？如果是这样，我可能会建议一个“使用PCB设计中的DA14580”题为“使用DA14580”的应用程序，以及任何其他关键信息。
2. Looking at the diagram for the coin cell on page 143 we see that it highlights the 32.768kHz crystal as 'optional'. So we deduce that if we use a supply voltage below 3.0V the 32.768kHz crystal is now optional. But by the answer/link above, we deduce that "If you wish to use UART to debug/download firmware on YOUR PCB, then you MUST HAVE A 32.768kHZ oscillator in YOUR CIRCUIT." Is this true? Again, an app note telling us this would really be a time saver during development.
So in summary, it would be great if you guys could put together an application note that lists the things we need to account for in our PCB design, the information seems to be 'buried in the weeds'. Thanks in advance for your response, mostly you guys do a good job answering the questions we ask, but sometimes the answer is not completely clear. --Klim
Hi,
The Murata module indeed has the 16MHz crystal on-board. The 32kHz (or 32.768kHz) external crystal is not required unless you have a use scanario where you sleep for more than 4 seconds at the time. Not having the 32kHz crystal will add an average of 4.5uA to your current consumption while you are in a BT connected state. In all other states (advertising, idle) the power consumption will be the same whether or not you have an external crystal.
You do not need the 32kHz crystal for UART or SPI. It is possible to use the 32kHz clock for these peripheral interfaces, but it would provide very low baudrates, besides requiring an external crystal. The 32kHz is not used as a periperal clock for any of our sample applications and certainly not the boot loader.
Hi MHv_Dialog,
I cannot thank you enough for the quick reply and the very specific answers to my questions!!
What I have found during development with the DA14580 is that, often, the answer that I am looking for is buried somewhere in all the documentation.
Its great to be able to get clear answers to questions without spending countless hours poring over datasheets and app notes, hoping that something will jump out at me.
It's somewhat frustrating to discover a problem similar to, or even exactly like, a problem that I am experiencing, where the problem resolution is not posted or made known.
Therefore, as I work through the problems that I encounter, I try to dutifully post my solutions to the forum, as you have done MHv_Dialog, in an equally clear and precise way.
+10 for your efforts, ---klim