diff options
Diffstat (limited to 'src/mem')
-rw-r--r-- | src/mem/DRAMCtrl.py | 111 |
1 files changed, 90 insertions, 21 deletions
diff --git a/src/mem/DRAMCtrl.py b/src/mem/DRAMCtrl.py index c53e90e87..8c573ca3a 100644 --- a/src/mem/DRAMCtrl.py +++ b/src/mem/DRAMCtrl.py @@ -175,9 +175,9 @@ class DRAMCtrl(AbstractMemory): # 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. +# A single DDR3-1600 x64 channel (one command and address bus), with +# timings based on a DDR3-1600 4 Gbit datasheet (Micron MT41J512M8) in +# an 8x8 configuration, amounting to 4 Gbyte of memory. class DDR3_1600_x64(DRAMCtrl): # 8x8 configuration, 8 devices each with an 8-bit interface device_bus_width = 8 @@ -185,8 +185,7 @@ class DDR3_1600_x64(DRAMCtrl): # DDR3 is a BL8 device burst_length = 8 - # Each device has a page (row buffer) size of 1KB - # (this depends on the memory density) + # Each device has a page (row buffer) size of 1 Kbyte (1K columns x8) device_rowbuffer_size = '1kB' # 8x8 configuration, so 8 devices @@ -201,37 +200,107 @@ class DDR3_1600_x64(DRAMCtrl): # 800 MHz tCK = '1.25ns' - # DDR3-1600 11-11-11-28 + # 8 beats across an x64 interface translates to 4 clocks @ 800 MHz + tBURST = '5ns' + + # DDR3-1600 11-11-11 tRCD = '13.75ns' tCL = '13.75ns' tRP = '13.75ns' tRAS = '35ns' + tRRD = '6ns' + tXAW = '30ns' + activation_limit = 4 + tRFC = '260ns' + tWR = '15ns' - tRTP = '7.5ns' - # 8 beats across an x64 interface translates to 4 clocks @ 800 MHz. - # Note this is a BL8 DDR device. - tBURST = '5ns' + # Greater of 4 CK or 7.5 ns + tWTR = '7.5ns' - # DDR3, 4 Gbit has a tRFC of 240 CK and tCK = 1.25 ns - tRFC = '300ns' + # Greater of 4 CK or 7.5 ns + tRTP = '7.5ns' - # DDR3, <=85C, half for >85C + # Default read-to-write bus around to 2 CK, @800 MHz = 2.5 ns + tRTW = '2.5ns' + + # <=85C, half for >85C tREFI = '7.8us' - # Greater of 4 CK or 7.5 ns, 4 CK @ 800 MHz = 5 ns - tWTR = '7.5ns' +# A single DDR3-2133 x64 channel refining a selected subset of the +# options for the DDR-1600 configuration, based on the same DDR3-1600 +# 4 Gbit datasheet (Micron MT41J512M8). Most parameters are kept +# consistent across the two configurations. +class DDR3_2133_x64(DDR3_1600_x64): + # 1066 MHz + tCK = '0.938ns' + + # 8 beats across an x64 interface translates to 4 clocks @ 1066 MHz + tBURST = '3.752ns' + + # DDR3-2133 14-14-14 + tRCD = '13.09ns' + tCL = '13.09ns' + tRP = '13.09ns' + tRAS = '33ns' + tRRD = '5ns' + tXAW = '25ns' + +# A single DDR4-2400 x64 channel (one command and address bus), with +# timings based on a DDR4-2400 4 Gbit datasheet (Samsung K4A4G085WD) +# in an 8x8 configuration, amounting to 4 Gbyte of memory. +class DDR4_2400_x64(DRAMCtrl): + # 8x8 configuration, 8 devices each with an 8-bit interface + device_bus_width = 8 - # Default read-to-write bus around to 2 CK, @800 MHz = 2.5 ns - tRTW = '2.5ns' + # DDR4 is a BL8 device + burst_length = 8 + + # Each device has a page (row buffer) size of 1 Kbyte (1K columns x8) + device_rowbuffer_size = '1kB' + + # 8x8 configuration, so 8 devices + devices_per_rank = 8 + + # Use a single rank + ranks_per_channel = 1 - # Assume 5 CK for activate to activate for different banks - tRRD = '6.25ns' + # DDR4 has 16 banks (4 bank groups) in all + # configurations. Currently we do not capture the additional + # constraints incurred by the bank groups + banks_per_rank = 16 - # With a 2kbyte page size, DDR3-1600 lands around 40 ns - tXAW = '40ns' + # 1200 MHz + tCK = '0.833ns' + + # 8 beats across an x64 interface translates to 4 clocks @ 1200 MHz + tBURST = '3.333ns' + + # DDR4-2400 17-17-17 + tRCD = '14.16ns' + tCL = '14.16ns' + tRP = '14.16ns' + tRAS = '32ns' + + # Here using the average of RRD_S and RRD_L + tRRD = '4.1ns' + tXAW = '21ns' activation_limit = 4 + tRFC = '260ns' + + tWR = '15ns' + # Here using the average of WTR_S and WTR_L + tWTR = '5ns' + + # Greater of 4 CK or 7.5 ns + tRTP = '7.5ns' + + # Default read-to-write bus around to 2 CK, @1200 MHz = 1.666 ns + tRTW = '1.666ns' + + # <=85C, half for >85C + tREFI = '7.8us' # A single DDR3 x64 interface (one command and address bus), with # default timings based on DDR3-1333 4 Gbit parts in an 8x8 |