Hi All:
I have a AD5522 Evaluation Board,and it's work well on Evaluation Software 1.6.1.
Now I want to use my STM32F103ZE to control the AD5522,but I can't communicate with AD5522 via SPI.
It's Evaluation Software timing,I want to read system control register,so I click READ SYSTEM CONTROL REGISTER ,and then, the software will send 0x10000000 to AD5522,and AD5522 will return 0x00000020 to me, it's work well in anytime.
Write 0x10000000
![a.JPG]()
Read 0x000020 (Default value when AD5522 power on)
![b.JPG]()
Now,I want to use my STM32F103ZE to read system control register,so I connect STM32F103ZE and AD5522,and remove the LK9 to disable USB function.As show below picture.
![ad55.png]()
The first time,STM32F103ZE will send the command 0x10000000 to AD5522,that meaning read system control register
![c.JPG]()
And then,STM32F103ZE will send 0xFFFFFF try to read data from AD5522, but the Busy pin goes low when 19th rising clock edge of SPI-CLOCK? Even so the result is 0x000020,that is true.
![d.JPG]()
But the second time,STM32F103ZE send the command 0x10000000 to AD5522 again,the Busy pin goes low when 5th rising clock edge of SPI-CLOCK and 31th rising clock edge.
![e.JPG]()
And then ,result is 0x000000,that's wrong(0x000020 is true).
![f.JPG]()
Simulation SPI Code:
uint32_t AD5522_SPI(uint16_t bits, uint32_t dat)
{
uint32_t Recvice = 0;
uint8_t i;
AD5522_CS_L;
AD5522_Delay(2);
//bits = 32 when write data to AD5522 and bits = 24 when read data from AD5522
for(i = 0; i < bits; i++)
{
if(dat & 0x80000000) //MSB
{
AD5522_MOSI_H;
}
else
{
AD5522_MOSI_L;
}
//CLOCK High
AD5522_CLK_H;
dat <<= 1;
Recvice <<= 1;
AD5522_Delay(1);
AD5522_CLK_L;
if(AD5522_MISO) //Read data when CLOCK falling edge.
{
Recvice++;
}
AD5522_Delay(3)
}
AD5522_Delay(1);
AD5522_CS_H;
AD5522_CLK_L; //Idle time,CLOCK is low
AD5522_MOSI_L; //Idle time,MOSI is low
return Recvice;
}
This problem puzzle me three days,can you help me?
sorry for my bad English.
thanks.
