CC110L writing RF registers

Naneet Kaur

Other Parts Discussed in Thread: CC110L, CC1101

Hi,

I am using CC110L for a project and I have few questions about it. After going through datasheet and forum, the process of using it is resetting it first (using SRES) then write configuration registers to complete the initialization.

So,1) when writing the configuration registers, should Csn be low for one config reg (for both address and data) and go high. Then for another config register it goes low again and back high.

2) For every config register, what should we get on the MISO ? For example, if writing to IOCFG2 , address is 0x00 and data is say 0x06, so the format is-

Csn goes low,

MOSI-Write 0x00,0x06

MISO-? What should we get here?

Csn goes high.

3) It says in the datasheet that "Registers with consecutive addresses can be accessed in an efficient way by setting the burst bit (B) in
the header byte". So, config registers have consecutive address, we can use burst access here. So, what is the correct procedure for that? For example, IOCF2 address is 0x00 and data value is 0x06 and IOCFG1 is0x01 and data value is 0x07 and so on. So, if we set the burst access to one, will the format be -

Csn low.

MOSI-0x40, 0x06, 0x07 and so on.

MISO-??(What will be here?)

Csn high.
Kindly tell if this is the correct way.

Thanks,

Navneet

over 8 years ago

0 Siri over 8 years ago

TI__Guru* 79421 points

You can write the register with single access, menaing that you send (address, data), (address, data), … CSn will be low for each address, data pair and go high in-between. If you are writing to many registers in a row you can do this using burst access. You then send the address of the first register you are accessing (with the burst bit set) and then you send data, data, data, ….. In this case CSn needs to below for the address and all the following data.

The status byte described in table 5-2 is returned both when you send the address and the data. This is shown in figure 5-3. The values you receive depends on the state of you chip and you FIFO content. If you are in IDLE with empty FIFO, the status byte will be 0x00.

This is correct. The status byte will be received for every byte written.

Siri

0 Naneet Kaur over 8 years ago in reply to Siri

Prodigy 90 points

Hi Siri,

OK got it ! . I have interfaced CC110L with other micro controller. So, Is there any way to check our radio chip is initialized correctly. Like If I send some command , it gives back part number or something to make sure that SPI is working properly.

Thanks,
Navneet

0 TER over 8 years ago in reply to Naneet Kaur

TI__Guru**** 317180 points

Try to read out the VERSION register and see if you get 0x07 or 0x17

0 Naneet Kaur over 8 years ago in reply to TER

Prodigy 90 points

Hi,

Yep, I got the SPI working. Thanks a lot !! :)
But I have one more question. I have used CC110L as receiver.After resetting, writing to config registers,and setting it as a receiver (using 0x34), I receive the packet correctly for one time. After that for the second incoming packet, the contents get shifted .
For example- transmitted packet (everytime) - 'a' 'b' 'c' 'd' 'e' 'f' 'g'
packet 1 (7 bytes)- 'a' 'b' 'c' 'd' 'e' 'f' 'g'
packet 2 (7 bytes)-'>' '!' ' 'a' 'b' 'c' 'd' 'e'

It gets filled with some random values. So is there any way to reset the FIFO?

Thanks,
Navneet

0 TER over 8 years ago in reply to Naneet Kaur

TI__Guru**** 317180 points

If you send a different packet the second time ('1' '2' '3' '4' '5' '6' '7' as an example) what do you read from the FIFO then? I suspect that you don't read out the correct number of bytes.

0 Naneet Kaur over 8 years ago in reply to TER

Prodigy 90 points

Hi,
Yep, now I am getting the correct packet but it just reads till 16 bytes. I am using variable packet length mode and i define the packet length as 0x0f. For example- In smartrf, I am sending- (in hex) 0f1122334455667788990011223344 (15bytes) and I receive data in an array(it is an array of 64 bytes) as-
array[0]= 0xf //What is this value??
array[1]=0xf //i got to understand that this is the length of the packet
array[2]= 0xf //packet starts from here
array[3]=0x11 //correct
array[4]=0x22 //correct
array[5]=0x33 //correct
array[6]=0x44 //correct
array[7]=0x55 //correct
array[8]=0x66 //correct
array[9]=0x77 //correct
array[10]=0x88 //correct
array[11]=0x99 //correct
array[12]=0x00 //correct
array[13]=0x11 //correct
array[14]=0x22 //correct
array[15]=0x33 //it is correct till here
array[16]=0x5a //what is this value? is this the status byte which is appended at the end?(RSSI?) (It should have got values from the data packet i.e. 0x44)
array[17]=0xab //same as above, (is this CRC byte??)
array[18]=0xf
array[19]=0x11
array[20]=0x22
array[21]=0x33
array[22]=0x44
array[23]='c'
array[24]=0xac
array[25]=0x12
array[26]=0xa0
array[27]=0x13

and random values so on till array[63].

Everytime I get the correct value till array[15]. Can you suggest if I am missing anything to read values from FIFO more than 16 bytes??

Thanks,
Navneet

0 TER over 8 years ago in reply to Naneet Kaur

TI__Guru**** 317180 points

You are not saying too much on how you get the data from the RXFIFO into your array. It could sound like you start copy the data from the wrong location. I assume you turn off the sequence number when sending from SmartRF Studio.

The below shows how we do in in our example code:

while(1)

{

// wait for packet received interrupt

if(packetSemaphore == ISR_ACTION_REQUIRED)

{

cc1101SpiReadReg(CC1101_RXBYTES,&rxBytesVerify,1);

{

rxBytes = rxBytesVerify;

cc1101SpiReadReg(CC1101_RXBYTES,&rxBytesVerify,1);

}

while(rxBytes != rxBytesVerify);

cc1101SpiReadRxFifo(rxBuffer,(rxBytes));

// check CRC ok (CRC_OK: bit7 in second status byte)

if(rxBuffer[rxBytes-1] & 0x80)

{

// update packet counter

packetCounter++;

}

// update LCD

updateLcd();

// reset packet semaphore

packetSemaphore = ISR_IDLE;

// set radio back in RX

trxSpiCmdStrobe(CC1101_SRX);

}

0 Naneet Kaur over 8 years ago in reply to TER

Prodigy 90 points

Hi,

I wrote a code based on this code only but I am not using interrupts right now. I am polling the length of data from RX_BYTES status register and always get 16. I think that's the reason I can read till 16 bytes only. After that, I check for the RX overflow. If no overflow is there, I read the data packet from RX_FIFO . That data packet is array of 64 bytes where it gets filled up every time till first 16 bytes. What to do to read more than 16 bytes?

I don't understand the value for first byte. It is a random value. I can see the transmitted packet starts from fourth byte till 16th byte. After that its all random.

What is the purpose of adding sequence number? Yep, I had turned it off because I wanted to read the data packet from the first byte.

Right now-I sent "abcdefghijkl" with "add seq number" turned on.

I receive-

Can you explain the packet.data[0] value and why I did not received "ijkl" ?

Kindly help. Thanks and Regards,

Navneet

0 Sushrut Lagwankar over 8 years ago

Intellectual 535 points

Hey ,

I am using same CC110L for communication . As you have mentioned , you are writing 0x00 ( register address ) 0x06 ( register value ) on MOSI , So do you enter ( 0x3E ) For Writing PATABLE address before sending register address and register in single mode ?

Thank you .
Regards,
Sushrut Lagwankar.

Sub-1 GHz

Sub-1 GHz forum

CC110L writing RF registers