diff --git a/software/software.mk b/software/software.mk
index fd876a73e..a80d3de42 100644
--- a/software/software.mk
+++ b/software/software.mk
@@ -9,10 +9,16 @@ DEFINE+=$(defmacro)FREQ=$(FREQ)
 TOOLCHAIN_PREFIX:=riscv64-unknown-elf-
 CFLAGS=-Os -nostdlib -march=$(MFLAGS) -mabi=ilp32
 
+MFLAGS=$(MFLAGS_BASE)$(MFLAG_M)$(MFLAG_C)
+
+MFLAGS_BASE:=rv32i
+
+ifeq ($(USE_MUL_DIV),1)
+MFLAG_M=m
+endif
+
 ifeq ($(USE_COMPRESSED),1)
-MFLAGS=rv32imc
-else
-MFLAGS=rv32im
+MFLAG_C=c
 endif
 
 #INCLUDE
diff --git a/submodules/CPU b/submodules/CPU
index 613dc94b6..6d846dd84 160000
--- a/submodules/CPU
+++ b/submodules/CPU
@@ -1 +1 @@
-Subproject commit 613dc94b6a345e61556f5dd09184fca50041e24e
+Subproject commit 6d846dd84151ea166fecbe326dec89bf43a499cb
diff --git a/system.mk b/system.mk
index 6d8bb4eed..4c24894c8 100644
--- a/system.mk
+++ b/system.mk
@@ -33,6 +33,9 @@ INIT_MEM ?=1
 #PERIPHERALS:=UART
 PERIPHERALS ?=UART
 
+#RISC-V HARD MULTIPLIER AND DIVIDER INSTRUCTIONS
+USE_MUL_DIV ?=1
+
 #RISC-V COMPRESSED INSTRUCTIONS
 USE_COMPRESSED ?=1