I would be very grateful for some help checking my workings for the transfer of 512-bytes in words (rates at 4.77MHz):
Port based:
8088:
IN 12
STOW 15
LOOP 5 => 7,424 clocks, 320KB/s
V20: REP INM 9 + 16*rep => 4,105 clocks, 580KB/s
Memory-mapped:
8088: REP MOVSW 9 + 25*rep => 6,409 clocks, 372KB/s
V20: REP MOVKW 11 + 16*rep => 4,107 clocks, 580KB/s
Do these scale directly with clock, i.e. would an 8MHz V20 be running at 970KB/s?
Many thanks!
Port based:
8088:
IN 12
STOW 15
LOOP 5 => 7,424 clocks, 320KB/s
V20: REP INM 9 + 16*rep => 4,105 clocks, 580KB/s
Memory-mapped:
8088: REP MOVSW 9 + 25*rep => 6,409 clocks, 372KB/s
V20: REP MOVKW 11 + 16*rep => 4,107 clocks, 580KB/s
Do these scale directly with clock, i.e. would an 8MHz V20 be running at 970KB/s?
Many thanks!