diff --git a/src/power.c b/src/power.c
index 50e06e9..848159c 100644
--- a/src/power.c
+++ b/src/power.c
@@ -4,7 +4,23 @@
 #include "bits.h"
 #include "power.h"
 
-
+/*
+   required units:
+   * SSP0 (FPGA interface) [enabled via spi_init]
+   * UART3 (debug console) [enabled via uart_init]
+   * TIM3 (FPGA clock)
+   * RTC
+   * GPIO
+   * GPDMA [enabled via spi_init]
+   * USB [enabled via usb_init]
+   * PWM1
+*/
 void power_init() {
-  LPC_SC->PCONP |= (BV(PCTIM3) | BV(PCUART3));
+  LPC_SC->PCONP = BV(PCSSP0)
+                | BV(PCTIM3)
+                | BV(PCRTC)
+                | BV(PCGPIO)
+                | BV(PCPWM1)
+//                 | BV(PCUSB)
+  ;
 }
diff --git a/src/power.h b/src/power.h
index a3b73fd..65d3cac 100644
--- a/src/power.h
+++ b/src/power.h
@@ -5,9 +5,38 @@
 
 #include "bits.h"
 
-#define PCUART3 (25)
 #define PCUART0	(3)
+#define PCUART1 (4)
+#define PCUART2 (24)
+#define PCUART3 (25)
+
+#define PCTIM0  (1)
+#define PCTIM1  (2)
+#define PCTIM2  (22)
 #define PCTIM3  (23)
+#define PCRTC   (9)
+#define PCRIT   (16)
+
+#define PCCAN1  (13)
+#define PCCAN2  (14)
+
+#define PCPWM1  (6)
+#define PCMCPWM (17)
+
+#define PCSSP0  (21)
+#define PCSSP1  (10)
+#define PCSPI   (8)
+
+#define PCI2C0  (7)
+#define PCI2C1  (19)
+#define PCI2C2  (26)
+
+#define PCI2S   (27)
+#define PCGPDMA (29)
+#define PCENET  (30)
+#define PCUSB   (31)
+#define PCQEI   (18)
+#define PCGPIO  (15)
 
 void power_init(void);