litedram/bench/ddr4_mr_gen.py

175 lines
4.2 KiB
Python
Executable File

#!/usr/bin/env python3
#
# This file is part of LiteDRAM.
#
# Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause
import argparse
parser = argparse.ArgumentParser(description="DDR4 Mode Register settings generator for LiteDRAM.")
parser.add_argument("--list", action="store_true", help="List supported DDR4 settings.")
parser.add_argument("--cl", default="11", help="CAS Latency.")
parser.add_argument("--cwl", default="9", help="CAS Write Latency.")
parser.add_argument("--rtt_nom", default="40ohm", help="RTT_NOM value.")
parser.add_argument("--rtt_wr", default="120ohm", help="RTT_WR value.")
parser.add_argument("--ron", default="34ohm", help="RON value.")
args = parser.parse_args()
# DDR4 Timing settings -----------------------------------------------------------------------------
cl_to_mr0 = {
9: 0b00000,
10: 0b00001,
11: 0b00010,
12: 0b00011,
13: 0b00100,
14: 0b00101,
15: 0b00110,
16: 0b00111,
18: 0b01000,
20: 0b01001,
22: 0b01010,
24: 0b01011,
23: 0b01100,
17: 0b01101,
19: 0b01110,
21: 0b01111,
25: 0b10000,
26: 0b10001,
27: 0b10010,
28: 0b10011,
29: 0b10100,
30: 0b10101,
31: 0b10110,
32: 0b10111,
}
cwl_to_mr2 = {
9: 0b000,
10: 0b001,
11: 0b010,
12: 0b011,
14: 0b100,
16: 0b101,
18: 0b110,
20: 0b111
}
if args.list:
print("Supported DDR4 Timing settings:")
print("cl:")
for v in cl_to_mr0.keys():
print(f" - {v}")
print("cwl:")
for v in cwl_to_mr2.keys():
print(f" - {v}")
# DDR4 Electrical settings -------------------------------------------------------------------------
z_to_rtt_nom = {
"disabled" : 0b000,
"60ohm" : 0b001,
"120ohm" : 0b010,
"40ohm" : 0b011,
"240ohm" : 0b100,
"48ohm" : 0b101,
"80ohm" : 0b110,
"34ohm" : 0b111
}
z_to_rtt_wr = {
"disabled" : 0b000,
"120ohm" : 0b001,
"240ohm" : 0b010,
"high-z" : 0b011,
"80ohm" : 0b100,
}
z_to_ron = {
"34ohm" : 0b00,
"48ohm" : 0b01,
}
if args.list:
print("Supported DDR4 Electrical settings:")
print("rtt_nom:")
for v in z_to_rtt_nom.keys():
print(f" - {v}")
print("rtt_wr:")
for v in z_to_rtt_wr.keys():
print(f" - {v}")
print("ron:")
for v in z_to_ron.keys():
print(f" - {v}")
# DDR4 Mode Register formating ---------------------------------------------------------------------
if args.list:
exit()
def format_mr0(bl, cl, wr, dll_reset):
bl_to_mr0 = {
4: 0b10,
8: 0b00
}
wr_to_mr0 = {
10: 0b0000,
12: 0b0001,
14: 0b0010,
16: 0b0011,
18: 0b0100,
20: 0b0101,
24: 0b0110,
22: 0b0111,
26: 0b1000,
28: 0b1001,
}
mr0 = bl_to_mr0[bl]
mr0 |= (cl_to_mr0[cl] & 0b1) << 2
mr0 |= ((cl_to_mr0[cl] >> 1) & 0b111) << 4
mr0 |= ((cl_to_mr0[cl] >> 4) & 0b1) << 12
mr0 |= dll_reset << 8
mr0 |= (wr_to_mr0[wr] & 0b111) << 9
mr0 |= (wr_to_mr0[wr] >> 3) << 13
return mr0
def format_mr1(dll_enable, ron, rtt_nom):
mr1 = dll_enable
mr1 |= ((ron >> 0) & 0b1) << 1
mr1 |= ((ron >> 1) & 0b1) << 2
mr1 |= ((rtt_nom >> 0) & 0b1) << 8
mr1 |= ((rtt_nom >> 1) & 0b1) << 9
mr1 |= ((rtt_nom >> 2) & 0b1) << 10
return mr1
def format_mr2(cwl, rtt_wr):
mr2 = cwl_to_mr2[cwl] << 3
mr2 |= rtt_wr << 9
return mr2
print("DDR4 Timing Settings:")
print(f"cl: {args.cl}")
print(f"cwl: {args.cwl}")
print("DDR4 Electrical Settings:")
print(f"rtt_nom: {args.rtt_nom}")
print(f"rtt_wr: {args.rtt_wr}")
print(f"ron: {args.ron}")
print("Commands to be used with LiteX BIOS:")
print("sdram_mr_write 0 {:d}".format(format_mr0(
bl = 8,
cl = int(args.cl, 0),
wr = 10,
dll_reset = 0))
)
print("sdram_mr_write 1 {:d}".format(format_mr1(
dll_enable = 1,
ron = z_to_ron[args.ron],
rtt_nom = z_to_rtt_nom[args.rtt_nom]))
)
print("sdram_mr_write 2 {:d}".format(format_mr2(
cwl = int(args.cwl, 0),
rtt_wr = z_to_rtt_wr[args.rtt_wr]))
)