| ??? 12/02/03 10:18 Read: times |
#59767 - RE: RISC Responding to: ???'s previous message |
Hatem Zakaria wrote:
------------------------------- If the condition is satisfied, then the next instruc-tion is discarded and a NOP is exe-cuted instead,not like 8051 conditional jump at some different lolcation. Actually the manual says: DECFSZ Decrement f, Skip if 0 The contents of register âfâ are decremented. If the result is 1, the next instruction is executed. If the result is 0, then a NOP is executed instead, making it a 2TCY instruction. This means that if your skip instruction is instruction #1 then 1) Decrement f 2) if result is one, increment program counter and continue program execution (executing instruction #2) 3) if result is zero, increment program counter but execute a NOP instruction (thus effectively bypassing instruction #2) and continue program execution with instruction #3. So if you combine this with the GOTO instruction as instruction #2, you actually have a conditional branch instruction.... Well that's how I read the document... rgds Patrick |
