AnsweredAssumed Answered

Controlling AD9910 via Serial Port

Question asked by Marduk on Feb 9, 2011
Latest reply on Feb 16, 2011 by DSB

Hello, everyone! Sorry for the wall of text, but I tried to describe my problem as accurately as possible.

 

I have to control an AD9910 PCBZ via a RS232 port (with a TTL voltage adapter) to use it with Labview, but I'm not sure about how to insert information into all the registers to get full control.

I'm using a 200MHz function generator connected to the SYS_CLK port along with a 9.6KHz (RS232 baud rate) function generator connected to SCLK.

 

SDIO and SDO ports are connected to Tx and Rx respectively, and pins P_0, P_1, P_2, IO_RESET, DRHOLD, DRCTL, CSB, RESET, EXT_PWR_DWN are jumpered (cleared).

 

W1, W2 and W4 are disabled and jumpers W3, W5 and W6 were removed to allow direct control. The Unfiltered Output is being measured with a signal analyzer, and a Labview VI (one I found in a tutorial, called Basic Serial Write and Read) is being used to input the data into the registers.

 

Once everything was hooked up, I tried sending in several ways the following data:

0x00 (CFR1) – 00 00 00 00 02

(SDIO Input Only)

0x01 (CFR2) – 01 01 C0 08 20

(ASF Enabled, Internal I/O Update Active, SYNC_CLK enabled)

0x02 (CFR3) – 02 1F BF 40 00

(Divider disabled)

02 1F BF C0 00

(Divider enabled)

0x04 (I/O Update Rate) – 04 00 00 61 A8

(1ms)

0x0E (Profile_0) – 0E 3F FF 00 00 XX XX XX XX

(XX being the Frequency Tuning Word, being changed at will for testing)

 

Assuming the correct order of the registers is 04,00,01,02 and 0E, what I tried inputting (all together AND separately, one register at a time) was:
04 00 00 61 A8 00 00 00 00 02 01 01 C0 08 20 02 1F BF 40 00 0E 3F FF 00 00 80 00 00 00

Results seemed to be completely random, as the frequency would rarely change at all. I'm guessing the order of the inputs is wrong or some connection should or shouldn't be jumpered. Or maybe there is some kind of extra bit that I should be sending. I tried many things, but this is the configuration that generated some results.


Can anyone help me find what I am missing here? I've read the entire datasheet (for both the CI and the PCBZ) and found nothing.
Thanks in advance!

Marcel

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