08-23-2013, 10:20 AM
(This post was last modified: 08-23-2013, 10:25 AM by WrytXander.)
(08-23-2013, 01:09 AM)CMOSprinkles Wrote: I've had this discussion before, maybe you can shed some light on it; What combination of AND/OR/NOR would you use to get results like "!A" or "B-->A"? I understand how those functions can be combined to perform XOR/TRUE/NAND etc., but I can't figure out how to get IMPLIES/NIMPLIES results or A/B/!A/!B. Out of curiosity, how many ticks does the ALU take to calculate the longest operation? And since I can't get on the server and there are no pictures, could you at least tell me the dimensions of the computer?
Never mind about the functions, I saw your response to the same question in another thread. So you literally have to have a register that is always set as 0? It seems like there would be a better way, such as Guy's idea of having only a single OR gate with inverters on both inputs and flood carry to achieve any Boolean operation using only general registers.
Oh, the longest ALU operation is 8 ticks.
And yeah, that OR stuff. It actuaaly doesn't matter how you do it. Either the nor+zero register I told you, or the one Guy told you, It end up being "not (something)" in the high level. And as long as you jabe it donein one clock cycle, It is fine . And the Zer register. A huge persantage of the modern cpus have it, and it does not have to be a real physical register. Just an address with no data in it. But od you do not want to implent that, you should use a Zero immediate instead.
You have to have otherdata, (other then the one you are trying to invert) becouse we set two operand at each clock cycle. So of you dont want to input two, but instead one, you have to have some sort pf blank data. (Or full 1's instead of 0,s to achieve our desired effect )