CC2564: Pin definition，How to realize communication

user6533748

Intellectual 300 points

Part Number: CC2564

1.A25 pin：SLOW_ CLK_ IN， Must give a 32.768KHz clock signal? Is it OK set to no connect ?

2. A6 pin: how to connect nSHUTD? Pull directly up to VDD_1.8V is OK?

3.MCU and Bluetooth are connected by UART four signals. Do we need special command to realize communication？

4.Is the following circuit diagram OK（R100 NC）?

over 4 years ago

0 Vincent Rodriguez over 4 years ago

TI__Mastermind 28285 points

Hi,

Please refer to our datasheet and reference design for proper schematic and layout of the device. https://www.ti.com/tool/CC256XEM-RD

BR,

Vince

0 user6533748 over 4 years ago

Intellectual 300 points

Thanks for your reply!

According to the circuit diagram design, the following problems are encountered(Vbat is directly powered by battery, VDD_ 1v8 is transferred from Vbat through LDO):

1>When the 1.8V voltage is connected to the BT PCB, the 1.8V voltage will become 2.8V. Vbat value is normal.

2>The 26MHz crystal doesn't work.

What are the possible causes of the above problems? We look forward to your reply

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi User,

Are you using a custom PCB or TI EVM? How are you validating the crystal is not working?

BR,

Vince

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Hi Vince,

Good day!

We use our company's PCB with cc2564 scheme.

We use an oscilloscope to test the clock signal of the crystal oscillator. The input & output of the crystal oscillator has no waveform output

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi user,

Please submit a design review so we can into more depth on the issue - https://www.ti.com/tool/DUALMODE-BT-DESIGN-REVIEWS

BR,

Vince

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Hi Vince，

Thanks for your reply!

I filled in the checklist. It seems that there are many problems. Please help me to have a look.

In addition, my colleagues in charge of software got the following information: host needs FW by HCI of cc2564 for download, and need SDK of MCU(STM32L452) and cc2564.My colleague has already sent another request for this problem. Will this affect the work of 26MHz crystal oscillator?

Best regards!

Lisa

CC2564_Hardware_Design_Checklist_20210202.xlsx

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi Lisa,

Give me another day to review your schematic.

BR,

Vince

0 Vincent Rodriguez over 4 years ago in reply to Vincent Rodriguez

TI__Mastermind 28285 points

Hi Lisa,

Are you able to toggle nShutdown?

BR,

Vince

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Hi Vince,

The nshutd signal can be connected to the GPIO port of MCU to realize high-low level conversion.

Is it suspected that nshutd caused 26MHz not working? And 1.8V abnormal voltage?

I can have a try.

PS:In general, should there be a 26MHz clock singnal after power on?

Best Regards.

Lisa

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Hi Vince，

I'm sorry to clarify a point：

The abnormal voltage of 1.8V is not caused by Bluetooth, but by PMIC.I'm very sorry for the trouble.

Now voltage of 1.8V is normal, the input & output of 26MHz still looks abnormal.
I tried to switch the signal state of nSHUTD and found that the UART waveform was different.
The measured waveforms are attached for your reference.

Best Regards!
Lisa

waveform.xlsx

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi User,

Looks like you are getting clock signals - The 26MHz is being effected by your measurement and the additional capacitance is causing the flattening of the signal.

Looks like you are getting UART TX and RX to and from the device, which means the device is functional. What are you using to send data over UART to the device? Are you using HCI Tester? Can you also use a logic analyzer to interpret the UART data that is flowing between the device?

Thanks,

Vince

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Hi Vince,

We use stm32l452 to communicate with cc2564 through UART signal, but it can't be realized in software at present.

If there is no problem with the cc2564 hardware, we can only wait for the software program to be OK, but it seems very difficult.

Do you have any good suggestions for that?

look forward to your reply!

Best Regards!

Lisa

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi Lisa,

You can use our evaluation boards to help development further without having your SW ready.

BR,

Vince

0 user6533748 over 4 years ago in reply to Vincent Rodriguez

Intellectual 300 points

Dear Vince,

Good day!

Can you help to provide IC software of development board?Can we write software directly to our board?

BR,

Lisa

0 Vincent Rodriguez over 4 years ago in reply to user6533748

TI__Mastermind 28285 points

Hi Lisa,

Take a look here for more info on how to get started with the EVMs and SW development: https://www.ti.com/lit/sg/swru523b/swru523b.pdf

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CC2564: Pin definition，How to realize communication