targets/nexys4ddr: update add_sdcard method.

Tested with:
sdinit
sdtestwrite 0x10 foobar
sdtestread 0x10

litex/boards/targets/nexys4ddr.py

@@ -25,7 +25,9 @@ from litesdcard.phy import SDPHY
 from litesdcard.clocker import SDClockerS7
 from litesdcard.core import SDCore
 from litesdcard.bist import BISTBlockGenerator, BISTBlockChecker
+from litesdcard.data import SDDataReader, SDDataWriter
 from litex.soc.cores.timer import Timer
+from litex.soc.interconnect import wishbone
 
 # CRG ----------------------------------------------------------------------------------------------
 
@@ -53,6 +55,10 @@ class _CRG(Module):
 # BaseSoC ------------------------------------------------------------------------------------------
 
 class BaseSoC(SoCCore):
+    mem_map = {**SoCCore.mem_map, **{
+            "sdread":       0x80002000, # len: 0x200
+            "sdwrite":      0x80002200, # len: 0x200
+        }}
     def __init__(self, sys_clk_freq=int(75e6), with_ethernet=False, **kwargs):
         platform = nexys4ddr.Platform()
 
@@ -93,27 +99,49 @@ class BaseSoC(SoCCore):
             sys_clk_freq = sys_clk_freq)
         self.add_csr("leds")
 
-    def add_sdcard(self):
+    def add_sdcard(self, memory_size=512, memory_width=32):
         sdcard_pads = self.platform.request("sdcard")
         if hasattr(sdcard_pads, "rst"):
             self.comb += sdcard_pads.rst.eq(0)
         self.submodules.sdclk = SDClockerS7(sys_clk_freq=self.sys_clk_freq)
         self.submodules.sdphy = SDPHY(sdcard_pads, self.platform.device)
-        self.submodules.sdcore = SDCore(self.sdphy)
+        self.submodules.sdcore = SDCore(self.sdphy, csr_data_width=self.csr_data_width)
         self.submodules.sdtimer = Timer()
         self.add_csr("sdclk")
         self.add_csr("sdphy")
         self.add_csr("sdcore")
         self.add_csr("sdtimer")
 
-        self.submodules.bist_generator = BISTBlockGenerator(random=True)
-        self.submodules.bist_checker = BISTBlockChecker(random=True)
-        self.add_csr("bist_generator")
-        self.add_csr("bist_checker")
-        self.comb += [
-            self.sdcore.source.connect(self.bist_checker.sink),
-            self.bist_generator.source.connect(self.sdcore.sink)
-        ]
+        # SD Card data reader
+
+        sdread_mem = Memory(memory_width, memory_size//4)
+        sdread_sram = FullMemoryWE()(wishbone.SRAM(sdread_mem, read_only=True))
+        self.submodules += sdread_sram
+
+        self.add_wb_slave(self.mem_map["sdread"], sdread_sram.bus, memory_size)
+        self.add_memory_region("sdread", self.mem_map["sdread"], memory_size)
+
+        sdread_port = sdread_sram.mem.get_port(write_capable=True);
+        self.specials += sdread_port
+        self.submodules.sddatareader = SDDataReader(port=sdread_port, endianness=self.cpu.endianness)
+        self.add_csr("sddatareader")
+        self.comb += self.sdcore.source.connect(self.sddatareader.sink),
+
+        # SD Card data writer
+
+        sdwrite_mem = Memory(memory_width, memory_size//4)
+        sdwrite_sram = FullMemoryWE()(wishbone.SRAM(sdwrite_mem, read_only=False))
+        self.submodules += sdwrite_sram
+
+        self.add_wb_slave(self.mem_map["sdwrite"], sdwrite_sram.bus, memory_size)
+        self.add_memory_region("sdwrite", self.mem_map["sdwrite"], memory_size)
+
+        sdwrite_port = sdwrite_sram.mem.get_port(write_capable=False, async_read=True, mode=READ_FIRST);
+        self.specials += sdwrite_port
+        self.submodules.sddatawriter = SDDataWriter(port=sdwrite_port, endianness=self.cpu.endianness)
+        self.add_csr("sddatawriter")
+        self.comb += self.sddatawriter.source.connect(self.sdcore.sink),
+
         self.platform.add_period_constraint(self.sdclk.cd_sd.clk, period_ns(self.sys_clk_freq))
         self.platform.add_period_constraint(self.sdclk.cd_sd_fb.clk, period_ns(self.sys_clk_freq))
         self.platform.add_false_path_constraints(