diff --git a/examples/alpha250-4/adc-bram/test.py b/examples/alpha250-4/adc-bram/test.py
index 909ddaeae..84359592b 100644
--- a/examples/alpha250-4/adc-bram/test.py
+++ b/examples/alpha250-4/adc-bram/test.py
@@ -47,7 +47,7 @@
 ax.set_ylabel('ADC Raw data')
 ax.set_xlim((t_us[0], t_us[-1]))
 # ax.set_ylim((-2**15, 2**15))
-ax.set_ylim((-300, 300))
+ax.set_ylim((-32768, 32768))
 ax.legend(loc='upper right')
 fig.canvas.draw()
 
diff --git a/fpga/fpga.mk b/fpga/fpga.mk
index 8905e4d9e..b67586802 100644
--- a/fpga/fpga.mk
+++ b/fpga/fpga.mk
@@ -53,11 +53,11 @@ $(TMP_FPGA_PATH)/$(NAME).xpr: $(CONFIG_TCL) $(XDC) $(PROJECT_PATH)/*.tcl $(CORES
 fpga: $(BITSTREAM)
 
 $(BITSTREAM): $(TMP_FPGA_PATH)/$(NAME).xpr | $(TMP_FPGA_PATH)
-	$(VIVADO_BATCH) -source $(FPGA_PATH)/vivado/bitstream.tcl -tclargs $< $@
+	$(VIVADO_BATCH) -source $(FPGA_PATH)/vivado/bitstream.tcl -tclargs $< $@ $(N_CPUS)
 	@echo [$@] OK
 
 $(TMP_FPGA_PATH)/$(NAME).hwdef: $(TMP_FPGA_PATH)/$(NAME).xpr | $(TMP_FPGA_PATH)
-	$(VIVADO_BATCH) -source $(FPGA_PATH)/vivado/hwdef.tcl -tclargs $(TMP_FPGA_PATH)/$(NAME).xpr $(TMP_FPGA_PATH)/$(NAME).hwdef
+	$(VIVADO_BATCH) -source $(FPGA_PATH)/vivado/hwdef.tcl -tclargs $(TMP_FPGA_PATH)/$(NAME).xpr $(TMP_FPGA_PATH)/$(NAME).hwdef $(N_CPUS)
 	@echo [$@] OK
 
 # Build the block design in Vivado GUI
diff --git a/fpga/vivado/bitstream.tcl b/fpga/vivado/bitstream.tcl
index 62aa5e831..70adcd8a2 100644
--- a/fpga/vivado/bitstream.tcl
+++ b/fpga/vivado/bitstream.tcl
@@ -1,10 +1,11 @@
 set xpr_filename [lindex $argv 0]
 set bit_filename [lindex $argv 1]
+set nCPU [lindex $argv 2]
 
 open_project $xpr_filename
 
 if {[get_property PROGRESS [get_runs impl_1]] != "100%"} {
-  launch_runs impl_1 -to_step route_design
+  launch_runs impl_1 -to_step route_design -jobs $nCPU
   wait_on_run impl_1
 }
 
diff --git a/fpga/vivado/hwdef.tcl b/fpga/vivado/hwdef.tcl
index 328734dda..c4bf1962d 100644
--- a/fpga/vivado/hwdef.tcl
+++ b/fpga/vivado/hwdef.tcl
@@ -1,10 +1,11 @@
 set xpr_filename [lindex $argv 0]
 set hwdef_filename [lindex $argv 1]
+set nCPU [lindex $argv 2]
 
 open_project $xpr_filename
 
 if {[get_property PROGRESS [get_runs synth_1]] != "100%"} {
-  launch_runs synth_1
+  launch_runs synth_1 -jobs $nCPU
   wait_on_run synth_1
 }