1 files changed, 23 insertions, 0 deletions
diff --git a/rcc.cpp b/rcc.cpp
new file mode 100644
index 0000000..79bbc69
--- /dev/null
+++ b/rcc.cpp
@@ -0,0 +1,23 @@
+#include "rcc.h"
+#include "stm32.h"
+
+void rcc_init() {
+	// Set flash latency.
+	FLASH.ACR = 0x12;
+	
+	// Enable HSE.
+	RCC.CR |= 0x10000;
+	while(RCC.CR & 0x20000);
+	
+	// Configure and enable PLL.
+	RCC.CFGR = 0x1d0000;
+	RCC.CR |= 0x1000000;
+	while(RCC.CR & 0x2000000);
+	
+	// Switch to PLL.
+	RCC.CFGR |= 0x2;
+	while(!(RCC.CFGR & 0x8));
+	
+	// Set APB1 prescaler to /2.
+	RCC.CFGR |= 0x400;
+}