from fractions import Fraction
from math import ceil

from migen.fhdl.std import *
from migen.sim.generic import Proxy

from milkymist import lasmicon

MHz = 1000000
clk_freq = (83 + Fraction(1, 3))*MHz

clk_period_ns = 1000000000/clk_freq
def ns(t, margin=True):
	if margin:
		t += clk_period_ns/2
	return ceil(t/clk_period_ns)

sdram_phy = lasmicon.PhySettings(
	memtype="DDR",
	dfi_d=64, 
	nphases=2,
	rdphase=0,
	wrphase=1,
	cl=3,
	read_latency=5,
	write_latency=0
)

sdram_geom = lasmicon.GeomSettings(
	bank_a=2,
	row_a=13,
	col_a=10
)
sdram_timing = lasmicon.TimingSettings(
	tRP=ns(15),
	tRCD=ns(15),
	tWR=ns(15),
	tWTR=2,
	tREFI=ns(7800, False),
	tRFC=ns(70),
	
	req_queue_size=8,
	read_time=32,
	write_time=16
)

def decode_sdram(ras_n, cas_n, we_n, bank, address):
	elts = []
	if not ras_n and cas_n and we_n:
		elts.append("ACTIVATE")
		elts.append("BANK " + str(bank))
		elts.append("ROW " + str(address))
	elif ras_n and not cas_n and we_n:
		elts.append("READ\t")
		elts.append("BANK " + str(bank))
		elts.append("COL " + str(address))
	elif ras_n and not cas_n and not we_n:
		elts.append("WRITE\t")
		elts.append("BANK " + str(bank))
		elts.append("COL " + str(address))
	elif ras_n and cas_n and not we_n:
		elts.append("BST")
	elif not ras_n and not cas_n and we_n:
		elts.append("AUTO REFRESH")
	elif not ras_n and cas_n and not we_n:
		elts.append("PRECHARGE")
		if address & 2**10:
			elts.append("ALL")
		else:
			elts.append("BANK " + str(bank))
	elif not ras_n and not cas_n and not we_n:
		elts.append("LMR")
	return elts

class CommandLogger(Module):
	def __init__(self, cmd, rw=False):
		self.cmd = cmd
		if rw:
			self.comb += self.cmd.ack.eq(1)
	
	def do_simulation(self, s):
		elts = ["@" + str(s.cycle_counter)]
		cmdp = Proxy(s, self.cmd)
		elts += decode_sdram(cmdp.ras_n, cmdp.cas_n, cmdp.we_n, cmdp.ba, cmdp.a)
		if len(elts) > 1:
			print("\t".join(elts))

class DFILogger(Module):
	def __init__(self, dfi):
		self.dfi = dfi
	
	def do_simulation(self, s):
		dfip = Proxy(s, self.dfi)
		
		for i, p in enumerate(dfip.phases):
			elts = ["@" + str(s.cycle_counter) + ":" + str(i)]
			elts += decode_sdram(p.ras_n, p.cas_n, p.we_n, p.bank, p.address)
			if len(elts) > 1:
				print("\t".join(elts))