Re: A89: TIGCCLIB 2.0 released!
[Prev][Next][Index][Thread]
Re: A89: TIGCCLIB 2.0 released!
> dbra d0,\loop ; 10/14 (taken/not taken)
> 4 + 80*(12+8*12 + 8+8*12 + 8) + 79*10 + 14 = 18,408 clock cycles ?!?
> How did you end up with 1,442 clock cycles?
Motorola 68k User's Manual, Section 7.7, Table 7.10 says that DBcc is 18
cycles for false, 20 true (not the 10/14 you have above?) and I was only
counting the difference between the rolled and unrolled loop (or the time
taken just for the dbra command). So I used 79 loops untaken, 1 loop
untaken, or 79*18 + 20 = 1,442. Did I misinterpret sometyhing in the
booklet?
> Use a stopwatch and measure the (exact) time it takes for the calc to APD.
Turned on, started timer, and I'm leaving it idle next to me now - we're
expecting circa 300 seconds, correct? If it makes a difference, I believe
my batteries are running low but there's no indication yet (I left it
running overnight in the middle of a prog that had disabled auto-int 1 =)
And the total is: 7:45.21, or approximately 465 seconds. If we can safely
assume that battery level is a factor, I'd guess that HW2 is only
oscillating at 2/3 the speed - any idea why?
-Scott
Follow-Ups:
References: