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Diffstat (limited to 'src/mem/DRAMCtrl.py')
-rw-r--r-- | src/mem/DRAMCtrl.py | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/src/mem/DRAMCtrl.py b/src/mem/DRAMCtrl.py new file mode 100644 index 000000000..3237e602d --- /dev/null +++ b/src/mem/DRAMCtrl.py @@ -0,0 +1,421 @@ +# Copyright (c) 2012-2013 ARM Limited +# All rights reserved. +# +# The license below extends only to copyright in the software and shall +# not be construed as granting a license to any other intellectual +# property including but not limited to intellectual property relating +# to a hardware implementation of the functionality of the software +# licensed hereunder. You may use the software subject to the license +# terms below provided that you ensure that this notice is replicated +# unmodified and in its entirety in all distributions of the software, +# modified or unmodified, in source code or in binary form. +# +# Copyright (c) 2013 Amin Farmahini-Farahani +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer; +# redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution; +# neither the name of the copyright holders nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# +# Authors: Andreas Hansson +# Ani Udipi + +from m5.params import * +from AbstractMemory import * + +# Enum for memory scheduling algorithms, currently First-Come +# First-Served and a First-Row Hit then First-Come First-Served +class MemSched(Enum): vals = ['fcfs', 'frfcfs'] + +# Enum for the address mapping. With Ch, Ra, Ba, Ro and Co denoting +# channel, rank, bank, row and column, respectively, and going from +# MSB to LSB. Available are RoRaBaChCo and RoRaBaCoCh, that are +# suitable for an open-page policy, optimising for sequential accesses +# hitting in the open row. For a closed-page policy, RoCoRaBaCh +# maximises parallelism. +class AddrMap(Enum): vals = ['RoRaBaChCo', 'RoRaBaCoCh', 'RoCoRaBaCh'] + +# Enum for the page policy, either open, open_adaptive, close, or +# close_adaptive. +class PageManage(Enum): vals = ['open', 'open_adaptive', 'close', + 'close_adaptive'] + +# DRAMCtrl is a single-channel single-ported DRAM controller model +# that aims to model the most important system-level performance +# effects of a DRAM without getting into too much detail of the DRAM +# itself. +class DRAMCtrl(AbstractMemory): + type = 'DRAMCtrl' + cxx_header = "mem/dram_ctrl.hh" + + # single-ported on the system interface side, instantiate with a + # bus in front of the controller for multiple ports + port = SlavePort("Slave port") + + # the basic configuration of the controller architecture + write_buffer_size = Param.Unsigned(64, "Number of write queue entries") + read_buffer_size = Param.Unsigned(32, "Number of read queue entries") + + # threshold in percent for when to forcefully trigger writes and + # start emptying the write buffer + write_high_thresh_perc = Param.Percent(85, "Threshold to force writes") + + # threshold in percentage for when to start writes if the read + # queue is empty + write_low_thresh_perc = Param.Percent(50, "Threshold to start writes") + + # minimum write bursts to schedule before switching back to reads + min_writes_per_switch = Param.Unsigned(16, "Minimum write bursts before " + "switching to reads") + + # scheduler, address map and page policy + mem_sched_policy = Param.MemSched('frfcfs', "Memory scheduling policy") + addr_mapping = Param.AddrMap('RoRaBaChCo', "Address mapping policy") + page_policy = Param.PageManage('open_adaptive', "Page management policy") + + # enforce a limit on the number of accesses per row + max_accesses_per_row = Param.Unsigned(16, "Max accesses per row before " + "closing"); + + # pipeline latency of the controller and PHY, split into a + # frontend part and a backend part, with reads and writes serviced + # by the queues only seeing the frontend contribution, and reads + # serviced by the memory seeing the sum of the two + static_frontend_latency = Param.Latency("10ns", "Static frontend latency") + static_backend_latency = Param.Latency("10ns", "Static backend latency") + + # the physical organisation of the DRAM + device_bus_width = Param.Unsigned("data bus width in bits for each DRAM "\ + "device/chip") + burst_length = Param.Unsigned("Burst lenght (BL) in beats") + device_rowbuffer_size = Param.MemorySize("Page (row buffer) size per "\ + "device/chip") + devices_per_rank = Param.Unsigned("Number of devices/chips per rank") + ranks_per_channel = Param.Unsigned("Number of ranks per channel") + banks_per_rank = Param.Unsigned("Number of banks per rank") + # only used for the address mapping as the controller by + # construction is a single channel and multiple controllers have + # to be instantiated for a multi-channel configuration + channels = Param.Unsigned(1, "Number of channels") + + # timing behaviour and constraints - all in nanoseconds + + # the amount of time in nanoseconds from issuing an activate command + # to the data being available in the row buffer for a read/write + tRCD = Param.Latency("RAS to CAS delay") + + # the time from issuing a read/write command to seeing the actual data + tCL = Param.Latency("CAS latency") + + # minimum time between a precharge and subsequent activate + tRP = Param.Latency("Row precharge time") + + # minimum time between an activate and a precharge to the same row + tRAS = Param.Latency("ACT to PRE delay") + + # time to complete a burst transfer, typically the burst length + # divided by two due to the DDR bus, but by making it a parameter + # it is easier to also evaluate SDR memories like WideIO. + # This parameter has to account for burst length. + # Read/Write requests with data size larger than one full burst are broken + # down into multiple requests in the controller + tBURST = Param.Latency("Burst duration (for DDR burst length / 2 cycles)") + + # time taken to complete one refresh cycle (N rows in all banks) + tRFC = Param.Latency("Refresh cycle time") + + # refresh command interval, how often a "ref" command needs + # to be sent. It is 7.8 us for a 64ms refresh requirement + tREFI = Param.Latency("Refresh command interval") + + # write-to-read turn around penalty, assumed same as read-to-write + tWTR = Param.Latency("Write to read switching time") + + # minimum row activate to row activate delay time + tRRD = Param.Latency("ACT to ACT delay") + + # time window in which a maximum number of activates are allowed + # to take place, set to 0 to disable + tXAW = Param.Latency("X activation window") + activation_limit = Param.Unsigned("Max number of activates in window") + + # Currently rolled into other params + ###################################################################### + + # tRC - assumed to be tRAS + tRP + +# A single DDR3 x64 interface (one command and address bus), with +# default timings based on DDR3-1600 4 Gbit parts in an 8x8 +# configuration, which would amount to 4 Gbyte of memory. +class DDR3_1600_x64(DRAMCtrl): + # 8x8 configuration, 8 devices each with an 8-bit interface + device_bus_width = 8 + + # DDR3 is a BL8 device + burst_length = 8 + + # Each device has a page (row buffer) size of 1KB + # (this depends on the memory density) + device_rowbuffer_size = '1kB' + + # 8x8 configuration, so 8 devices + devices_per_rank = 8 + + # Use two ranks + ranks_per_channel = 2 + + # DDR3 has 8 banks in all configurations + banks_per_rank = 8 + + # DDR3-1600 11-11-11-28 + tRCD = '13.75ns' + tCL = '13.75ns' + tRP = '13.75ns' + tRAS = '35ns' + + # 8 beats across an x64 interface translates to 4 clocks @ 800 MHz. + # Note this is a BL8 DDR device. + tBURST = '5ns' + + # DDR3, 4 Gbit has a tRFC of 240 CK and tCK = 1.25 ns + tRFC = '300ns' + + # DDR3, <=85C, half for >85C + tREFI = '7.8us' + + # Greater of 4 CK or 7.5 ns, 4 CK @ 800 MHz = 5 ns + tWTR = '7.5ns' + + # Assume 5 CK for activate to activate for different banks + tRRD = '6.25ns' + + # With a 2kbyte page size, DDR3-1600 lands around 40 ns + tXAW = '40ns' + activation_limit = 4 + + +# A single DDR3 x64 interface (one command and address bus), with +# default timings based on DDR3-1333 4 Gbit parts in an 8x8 +# configuration, which would amount to 4 GByte of memory. This +# configuration is primarily for comparing with DRAMSim2, and all the +# parameters except ranks_per_channel are based on the DRAMSim2 config +# file DDR3_micron_32M_8B_x8_sg15.ini. Note that ranks_per_channel has +# to be manually set, depending on size of the memory to be +# simulated. By default DRAMSim2 has 2048MB of memory with a single +# rank. Therefore for 4 GByte memory, set ranks_per_channel = 2 +class DDR3_1333_x64_DRAMSim2(DRAMCtrl): + # 8x8 configuration, 8 devices each with an 8-bit interface + device_bus_width = 8 + + # DDR3 is a BL8 device + burst_length = 8 + + # Each device has a page (row buffer) size of 1KB + # (this depends on the memory density) + device_rowbuffer_size = '1kB' + + # 8x8 configuration, so 8 devices + devices_per_rank = 8 + + # Use two ranks + ranks_per_channel = 2 + + # DDR3 has 8 banks in all configurations + banks_per_rank = 8 + + tRCD = '15ns' + tCL = '15ns' + tRP = '15ns' + tRAS = '36ns' + + # 8 beats across an x64 interface translates to 4 clocks @ 666.66 MHz. + # Note this is a BL8 DDR device. + tBURST = '6ns' + + tRFC = '160ns' + + # DDR3, <=85C, half for >85C + tREFI = '7.8us' + + # Greater of 4 CK or 7.5 ns, 4 CK @ 666.66 MHz = 6 ns + tWTR = '7.5ns' + + tRRD = '6.0ns' + + tXAW = '30ns' + activation_limit = 4 + + +# A single LPDDR2-S4 x32 interface (one command/address bus), with +# default timings based on a LPDDR2-1066 4 Gbit part in a 1x32 +# configuration. +class LPDDR2_S4_1066_x32(DRAMCtrl): + # 1x32 configuration, 1 device with a 32-bit interface + device_bus_width = 32 + + # LPDDR2_S4 is a BL4 and BL8 device + burst_length = 8 + + # Each device has a page (row buffer) size of 1KB + # (this depends on the memory density) + device_rowbuffer_size = '1kB' + + # 1x32 configuration, so 1 device + devices_per_rank = 1 + + # Use a single rank + ranks_per_channel = 1 + + # LPDDR2-S4 has 8 banks in all configurations + banks_per_rank = 8 + + # Fixed at 15 ns + tRCD = '15ns' + + # 8 CK read latency, 4 CK write latency @ 533 MHz, 1.876 ns cycle time + tCL = '15ns' + + # Pre-charge one bank 15 ns (all banks 18 ns) + tRP = '15ns' + + tRAS = '42ns' + + # 8 beats across an x32 DDR interface translates to 4 clocks @ 533 MHz. + # Note this is a BL8 DDR device. + # Requests larger than 32 bytes are broken down into multiple requests + # in the controller + tBURST = '7.5ns' + + # LPDDR2-S4, 4 Gbit + tRFC = '130ns' + tREFI = '3.9us' + + # Irrespective of speed grade, tWTR is 7.5 ns + tWTR = '7.5ns' + + # Activate to activate irrespective of density and speed grade + tRRD = '10.0ns' + + # Irrespective of density, tFAW is 50 ns + tXAW = '50ns' + activation_limit = 4 + +# A single WideIO x128 interface (one command and address bus), with +# default timings based on an estimated WIO-200 8 Gbit part. +class WideIO_200_x128(DRAMCtrl): + # 1x128 configuration, 1 device with a 128-bit interface + device_bus_width = 128 + + # This is a BL4 device + burst_length = 4 + + # Each device has a page (row buffer) size of 4KB + # (this depends on the memory density) + device_rowbuffer_size = '4kB' + + # 1x128 configuration, so 1 device + devices_per_rank = 1 + + # Use one rank for a one-high die stack + ranks_per_channel = 1 + + # WideIO has 4 banks in all configurations + banks_per_rank = 4 + + # WIO-200 + tRCD = '18ns' + tCL = '18ns' + tRP = '18ns' + tRAS = '42ns' + + # 4 beats across an x128 SDR interface translates to 4 clocks @ 200 MHz. + # Note this is a BL4 SDR device. + tBURST = '20ns' + + # WIO 8 Gb + tRFC = '210ns' + + # WIO 8 Gb, <=85C, half for >85C + tREFI = '3.9us' + + # Greater of 2 CK or 15 ns, 2 CK @ 200 MHz = 10 ns + tWTR = '15ns' + + # Activate to activate irrespective of density and speed grade + tRRD = '10.0ns' + + # Two instead of four activation window + tXAW = '50ns' + activation_limit = 2 + +# A single LPDDR3 x32 interface (one command/address bus), with +# default timings based on a LPDDR3-1600 4 Gbit part in a 1x32 +# configuration +class LPDDR3_1600_x32(DRAMCtrl): + # 1x32 configuration, 1 device with a 32-bit interface + device_bus_width = 32 + + # LPDDR3 is a BL8 device + burst_length = 8 + + # Each device has a page (row buffer) size of 4KB + device_rowbuffer_size = '4kB' + + # 1x32 configuration, so 1 device + devices_per_rank = 1 + + # Use a single rank + ranks_per_channel = 1 + + # LPDDR3 has 8 banks in all configurations + banks_per_rank = 8 + + # Fixed at 15 ns + tRCD = '15ns' + + # 12 CK read latency, 6 CK write latency @ 800 MHz, 1.25 ns cycle time + tCL = '15ns' + + tRAS = '42ns' + + # Pre-charge one bank 15 ns (all banks 18 ns) + tRP = '15ns' + + # 8 beats across a x32 DDR interface translates to 4 clocks @ 800 MHz. + # Note this is a BL8 DDR device. + # Requests larger than 32 bytes are broken down into multiple requests + # in the controller + tBURST = '5ns' + + # LPDDR3, 4 Gb + tRFC = '130ns' + tREFI = '3.9us' + + # Irrespective of speed grade, tWTR is 7.5 ns + tWTR = '7.5ns' + + # Activate to activate irrespective of density and speed grade + tRRD = '10.0ns' + + # Irrespective of size, tFAW is 50 ns + tXAW = '50ns' + activation_limit = 4 |