diff --git a/CMSIS/Device/RaspberryPi/RP2040/Source/system_RP2040.c b/CMSIS/Device/RaspberryPi/RP2040/Source/system_RP2040.c
index c130714..4b9b073 100644
--- a/CMSIS/Device/RaspberryPi/RP2040/Source/system_RP2040.c
+++ b/CMSIS/Device/RaspberryPi/RP2040/Source/system_RP2040.c
@@ -34,7 +34,7 @@
 /*---------------------------------------------------------------------------
   System Core Clock Variable
  *---------------------------------------------------------------------------*/
-#define MacroSystemCoreClock (400 * 1000 * 1000)
+#define MacroSystemCoreClock (200 * 1000 * 1000)
 uint32_t SystemCoreClock; /* System Clock Frequency (Core Clock)*/
 volatile uint32_t tick_1ms;
 
@@ -54,8 +54,9 @@ void __attribute__((constructor)) SystemInit (void)
     system_regulator_set(SYSTEM_REGULATOR_VOLTAGE_1P30V);
     clock_ref_set_src(CLOCK_REF_SRC_XOSC_GLITCHLESS);
     clock_sys_set_src(CLOCK_SYS_SRC_REF_GLITCHLESS);
-    clock_pll_init(CLOCK_PLL_SYSPLL, 1, 100, 3, 1); /* 12MHz * 100 / 3 / 1 = 400MHz */
-    clock_sys_set_div(1 << 8);                      /* 400MHz / 1 = 400MHz */
+    /* refdiv >= 5MHz, VCO=[750:1600]MHz, fbdiv=[16:320], postdiv=[1:7] */
+    clock_pll_init(CLOCK_PLL_SYSPLL, 1, 100, 3, 2); /* 12MHz / 1 * 100 / 3 / 2 = 200MHz */
+    clock_sys_set_div(1 << 8);                      /* 200MHz / 1 = 200MHz */
     clock_sys_set_src(CLOCK_SYS_SRC_SYSPLL);
 
     SystemCoreClockUpdate();