65816 Prop Delay Timing Helper Program

r1timing.py

#!/usr/bin/env python

if __name__ == '__main__':
	#Python 3 compatibility stuff
	try:
		input = raw_input
	except:
		pass
	
	data_setup_time = 10
	addr_max_setup = 30
	freq_65xx = input('Desired 65816 frequency (MHz): ')
	glue_logic_delay_eprom_ce = input('Decoding delay from A0-A15 to ~CE (ns): ')
	#glue_logic_delay_eprom_ce = 0
	eprom_speed = (1000/float(freq_65xx) - data_setup_time) - addr_max_setup - float(glue_logic_delay_eprom_ce)
	print('Required EPROM speed w/ {0} glue logic (max access time): {1}'.format(glue_logic_delay_eprom_ce, eprom_speed))
	
	oe_not_prop = 8.5 #PHI inversion prop delay
	oe_373_prop = 10.4 #373 prop delay
	clk_to_oe_eprom = 0
	#Half the period b/c we need to wait for PHI2 rising edge
	oe_max_prop = (1000/(2*float(freq_65xx)) - data_setup_time) - oe_373_prop - oe_not_prop - clk_to_oe_eprom
	if oe_max_prop <= 0:
		print('OE requirement impossible to satisfy')
	else:
		print('Decoding delay from A16-23 to ~OE: {0}'.format(oe_max_prop))
		
	print('Required bank 0x1-0xFF RAM/EPROM speed w/o glue logic: {0}'.format(oe_max_prop))