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authorWendy Elsasser <wendy.elsasser@arm.com>2015-09-22 13:17:53 -0500
committerWendy Elsasser <wendy.elsasser@arm.com>2015-09-22 13:17:53 -0500
commit61c38524ceb9cf257feee73d60323da319145705 (patch)
tree2bad78df77b615fab6dae3b2d45bfddcf0ea897f /src
parent89750538648a11a8db9bd0704d000bb26367b87b (diff)
downloadgem5-61c38524ceb9cf257feee73d60323da319145705.tar.xz
mem: Add initial HBM configurations
Created the following HBM configurations: 1) HBM gen1 (x128/CH), 2Gb die, 4H stack, 1Gbps, 8 channels 2) HBM gen2 (x64/PC), 8Gb die, 4H stack, 1Gbps, 16 pseudo-channels The configuration values are based on: - The HBM gen1 public JEDEC spec - Publically released data from MemCon presentations - Timing extrapolated from existing LPDDR configurations Will adjust once specs become available.
Diffstat (limited to 'src')
-rw-r--r--src/mem/DRAMCtrl.py126
1 files changed, 126 insertions, 0 deletions
diff --git a/src/mem/DRAMCtrl.py b/src/mem/DRAMCtrl.py
index d02011526..171d99686 100644
--- a/src/mem/DRAMCtrl.py
+++ b/src/mem/DRAMCtrl.py
@@ -912,6 +912,132 @@ class GDDR5_4000_x64(DRAMCtrl):
# Assume 2 cycles
tRTW = '2ns'
+# A single HBM x128 interface (one command and address bus), with
+# default timings based on data publically released
+# ("HBM: Memory Solution for High Performance Processors", MemCon, 2014),
+# IDD measurement values, and by extrapolating data from other classes.
+# Architecture values based on published HBM spec
+# A 4H stack is defined, 2Gb per die for a total of 1GB of memory.
+class HBM_1000_4H_x128(DRAMCtrl):
+ # HBM gen1 supports up to 8 128-bit physical channels
+ # Configuration defines a single channel, with the capacity
+ # set to (full_ stack_capacity / 8) based on 2Gb dies
+ # To use all 8 channels, set 'channels' parameter to 8 in
+ # system configuration
+
+ # 128-bit interface legacy mode
+ device_bus_width = 128
+
+ # HBM supports BL4 and BL2 (legacy mode only)
+ burst_length = 4
+
+ # size of channel in bytes, 4H stack of 2Gb dies is 1GB per stack;
+ # with 8 channels, 128MB per channel
+ device_size = '128MB'
+
+ device_rowbuffer_size = '2kB'
+
+ # 1x128 configuration
+ devices_per_rank = 1
+
+ # HBM does not have a CS pin; set rank to 1
+ ranks_per_channel = 1
+
+ # HBM has 8 or 16 banks depending on capacity
+ # 2Gb dies have 8 banks
+ banks_per_rank = 8
+
+ # depending on frequency, bank groups may be required
+ # will always have 4 bank groups when enabled
+ # current specifications do not define the minimum frequency for
+ # bank group architecture
+ # setting bank_groups_per_rank to 0 to disable until range is defined
+ bank_groups_per_rank = 0
+
+ # 500 MHz for 1Gbps DDR data rate
+ tCK = '2ns'
+
+ # use values from IDD measurement in JEDEC spec
+ # use tRP value for tRCD and tCL similar to other classes
+ tRP = '15ns'
+ tRCD = '15ns'
+ tCL = '15ns'
+ tRAS = '33ns'
+
+ # BL2 and BL4 supported, default to BL4
+ # DDR @ 500 MHz means 4 * 2ns / 2 = 4ns
+ tBURST = '4ns'
+
+ # value for 2Gb device from JEDEC spec
+ tRFC = '160ns'
+
+ # value for 2Gb device from JEDEC spec
+ tREFI = '3.9us'
+
+ # extrapolate the following from LPDDR configs, using ns values
+ # to minimize burst length, prefetch differences
+ tWR = '18ns'
+ tRTP = '7.5ns'
+ tWTR = '10ns'
+
+ # start with 2 cycles turnaround, similar to other memory classes
+ # could be more with variations across the stack
+ tRTW = '4ns'
+
+ # single rank device, set to 0
+ tCS = '0ns'
+
+ # from MemCon example, tRRD is 4ns with 2ns tCK
+ tRRD = '4ns'
+
+ # from MemCon example, tFAW is 30ns with 2ns tCK
+ tXAW = '30ns'
+ activation_limit = 4
+
+ # 4tCK
+ tXP = '8ns'
+
+ # start with tRFC + tXP -> 160ns + 8ns = 168ns
+ tXS = '168ns'
+
+# A single HBM x64 interface (one command and address bus), with
+# default timings based on HBM gen1 and data publically released
+# A 4H stack is defined, 8Gb per die for a total of 4GB of memory.
+# Note: This defines a pseudo-channel with a unique controller
+# instantiated per pseudo-channel
+# Stay at same IO rate (1Gbps) to maintain timing relationship with
+# HBM gen1 class (HBM_1000_4H_x128) where possible
+class HBM_1000_4H_x64(HBM_1000_4H_x128):
+ # For HBM gen2 with pseudo-channel mode, configure 2X channels.
+ # Configuration defines a single pseudo channel, with the capacity
+ # set to (full_ stack_capacity / 16) based on 8Gb dies
+ # To use all 16 pseudo channels, set 'channels' parameter to 16 in
+ # system configuration
+
+ # 64-bit pseudo-channle interface
+ device_bus_width = 64
+
+ # HBM pseudo-channel only supports BL4
+ burst_length = 4
+
+ # size of channel in bytes, 4H stack of 8Gb dies is 4GB per stack;
+ # with 16 channels, 256MB per channel
+ device_size = '256MB'
+
+ # page size is halved with pseudo-channel; maintaining the same same number
+ # of rows per pseudo-channel with 2X banks across 2 channels
+ device_rowbuffer_size = '1kB'
+
+ # HBM has 8 or 16 banks depending on capacity
+ # Starting with 4Gb dies, 16 banks are defined
+ banks_per_rank = 16
+
+ # reset tRFC for larger, 8Gb device
+ # use HBM1 4Gb value as a starting point
+ tRFC = '260ns'
+
+ # start with tRFC + tXP -> 160ns + 8ns = 168ns
+ tXS = '268ns'
# Default different rank bus delay to 2 CK, @1000 MHz = 2 ns
tCS = '2ns'
tREFI = '3.9us'