DAC38RF89: Output summation block

Hi，Jim

But in table 44, when two channel added, it use bits 17:2  for the result, not bits 16:1. what's the reason?

Regards,

John

John,

With three 16 bit 2's comp numbers at max value added, will result in a 18 bit number. Bits 17:2 will then be used to create the 16 bit value. In this table, you always need to add 1 more channel to the first column.

Regards,

Jim

Jim,

With three channel added,it will be four 16 bit 2's comp numbers summation, It will result in a 18bit number. But in the table this is a 19 bit number, and it use bits 18:3 for the result. 

[18:3] is 16 bits. Not sure why you say 19 bits.

Jim,

  The sum is bits[18:0] (when three channel added) in the table,it is a 19bit number. But the table use bits 18:3 as result to send to DAC core.

  You said "In this table, you always need to add 1 more channel to the first column."

  So I think that It's the sum of four 16 bit 2's comp numbers when when three channel added.

Regards,

John.