sdram: create module.py to define SDRAM modules and use it on de0nano/ppro targets

misoclib/mem/sdram/module.py

@@ -0,0 +1,70 @@
+from math import ceil
+
+from migen.fhdl.std import *
+from misoclib.mem import sdram
+
+class SDRAMModule:
+	def __init__(self, clk_freq, geom_settings, timing_settings):
+		self.clk_freq = clk_freq
+		self.geom_settings = sdram.GeomSettings(
+			bank_a=log2_int(geom_settings["nbanks"]),
+			row_a=log2_int(geom_settings["nrows"]),
+			col_a=log2_int(geom_settings["ncols"])
+		)
+		self.timing_settings = sdram.TimingSettings(
+			tRP=self.ns(timing_settings["tRP"]),
+			tRCD=self.ns(timing_settings["tRCD"]),
+			tWR=self.ns(timing_settings["tWR"]),
+			tWTR=timing_settings["tWTR"],
+			tREFI=self.ns(timing_settings["tREFI"], False),
+			tRFC=self.ns(timing_settings["tRFC"])
+		)
+
+	def ns(self, t, margin=True):
+		clk_period_ns = 1000000000/self.clk_freq
+		if margin:
+			t += clk_period_ns/2
+		return ceil(t/clk_period_ns)
+
+# SDR
+class IS42S16160(SDRAMModule):
+	geom_settings = {
+		"nbanks": 	4,
+		"nrows":	8192,
+		"ncols":	512
+	}
+	timing_settings = {
+		"tRP":		20,
+		"tRCD":		20,
+		"tWR":		20,
+		"tWTR":		2,
+		"tREFI":	7800,
+		"tRFC":		70
+	}
+	def __init__(self, clk_freq):
+		SDRAMModule.__init__(self, clk_freq, self.geom_settings, self.timing_settings)
+
+class MT48LC4M16(SDRAMModule):
+	geom_settings = {
+		"nbanks":	4,
+		"nrows":	4096,
+		"ncols":	256
+	}
+	timing_settings = {
+		"tRP":		15,
+		"tRCD":		15,
+		"tWR":		14,
+		"tWTR":		2,
+		"tREFI":	64*1000*1000/4096,
+		"tRFC":		66
+	}
+	def __init__(self, clk_freq):
+		SDRAMModule.__init__(self, clk_freq, self.geom_settings, self.timing_settings)
+
+# DDR
+
+# LPDDR
+
+# DDR2
+
+# DDR3

targets/de0nano.py

@@ -3,6 +3,7 @@ from migen.bus import wishbone
 
 from misoclib.cpu.peripherals import gpio
 from misoclib.mem import sdram
+from misoclib.mem.sdram.module import IS42S16160
 from misoclib.mem.sdram.phy import gensdrphy
 from misoclib.com import uart
 from misoclib.soc.sdram import SDRAMSoC
@@ -90,27 +91,14 @@ class BaseSoC(SDRAMSoC):
 		self.submodules.crg = _CRG(platform)
 
 		if not self.with_main_ram:
-			sdram_geom_settings = sdram.GeomSettings(
-				bank_a=2,
-				row_a=13,
-				col_a=9
-			)
-
-			sdram_timing_settings = sdram.TimingSettings(
-				tRP=self.ns(20),
-				tRCD=self.ns(20),
-				tWR=self.ns(20),
-				tWTR=2,
-				tREFI=self.ns(7800, False),
-				tRFC=self.ns(70)
-			)
+			sdram_module = IS42S16160(self.clk_freq)
 			sdram_controller_settings = sdram.ControllerSettings(
 				req_queue_size=8,
 				read_time=32,
 				write_time=16
 			)
 			self.submodules.sdrphy = gensdrphy.GENSDRPHY(platform.request("sdram"))
-			self.register_sdram_phy(self.sdrphy, sdram_geom_settings, sdram_timing_settings,
+			self.register_sdram_phy(self.sdrphy, sdram_module.geom_settings, sdram_module.timing_settings,
 				sdram_controller_settings)
 
 default_subtarget = BaseSoC

targets/ppro.py

@@ -4,6 +4,7 @@ from migen.fhdl.std import *
 from migen.genlib.resetsync import AsyncResetSynchronizer
 
 from misoclib.mem import sdram
+from misoclib.mem.sdram.module import MT48LC4M16
 from misoclib.mem.sdram.phy import gensdrphy
 from misoclib.mem.flash import spiflash
 from misoclib.soc.sdram import SDRAMSoC
@@ -74,26 +75,14 @@ class BaseSoC(SDRAMSoC):
 		self.submodules.crg = _CRG(platform, clk_freq)
 
 		if not self.with_main_ram:
-			sdram_geom_settings = sdram.GeomSettings(
-				bank_a=2,
-				row_a=12,
-				col_a=8
-			)
-			sdram_timing_settings = sdram.TimingSettings(
-				tRP=self.ns(15),
-				tRCD=self.ns(15),
-				tWR=self.ns(14),
-				tWTR=2,
-				tREFI=self.ns(64*1000*1000/4096, False),
-				tRFC=self.ns(66)
-			)
+			sdram_module = MT48LC4M16(clk_freq)
 			sdram_controller_settings = sdram.ControllerSettings(
 				req_queue_size=8,
 				read_time=32,
 				write_time=16
 			)
 			self.submodules.sdrphy = gensdrphy.GENSDRPHY(platform.request("sdram"))
-			self.register_sdram_phy(self.sdrphy, sdram_geom_settings, sdram_timing_settings,
+			self.register_sdram_phy(self.sdrphy, sdram_module.geom_settings, sdram_module.timing_settings,
 				sdram_controller_settings)
 
 		self.submodules.spiflash = spiflash.SpiFlash(platform.request("spiflash2x"), dummy=4, div=6)