Hi,
I am working on a PMBUS project with HDK in a polling mode. I need a register or flag like UCD3138's PMBST- Data_Request bit.
I couldn't find which one i can use for the warn me when send request came.
What can i use for that?
Hi Gunce,
The data request bit in PMBST is same as SDIR bit in I2C
After RESET the initial value of this bit is 0 for device, that means the slave is operates in receiver mode. If a master sends the slave_address+ read command to the slave, then this bit will shift from 0 to 1.
So, if master requests data from slave SDIR bit will become 1 and if master wants to send data to the slave, then this bit will become zero on slave side.
The below is a simple slave code on i2c in polling mode.
In above code we are continuously polling AAS bit which will set when MASTER send address matches to the slave own address (in this case it is 0x4C), and this bit will be in set state until the master sends a STOP condition.
And after that we are verifying the SDIR bit, to find the direction. This SDIR bit will get sets if master sends a read request, and it will be zero if master sends a write request.
So here we are sending the data to the master if it sends a read request, and we are reading the data from the master if it sends a write request.
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Thanks & Regards,
Jagadish.
