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AD9548 SPI problem

Question asked by laserguy on Oct 1, 2014
Latest reply on Oct 6, 2014 by Kyle.Slightom

Dear Sir or Madam,

 

I have a problem of SPI communication(4-wire) with ARM core processor(Cortex-M3).

I think my circuit schematic is almost same with AD9548 Evaluation Board's schematic.

I'm trying to write/read with AD9548's registers.

My configurtion is as follows.

1. M0/M1/M2 pins  = 0(GND)

2. SCLK/SCL(AD9548) - SCLK(ARM), SDIO(AD9548)-MOSI(ARM), SDO(AD9548)-MISO(ARM), CSB/SDA(AD9548)-CS(ARM)

3. All lines of SPI are pull-up(4.7K)

4. W1/W0 = 0(1  byte to transfer)

 

with this conditions.

after power-on, I tried to write 0x80 to 0x0000 register(sireal configuration, only 4-wire bit enable)

and then when I read a 0x0002 and 0x0003 register(silicon revision level & Device ID), the results are always 0xff.

 

what does it wrong?

 

 

Please advise...

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