SDRAM - Raspberry Pi Hardware Reference - page 37

Figure 4-1. Physical memory layout

In the region labeled Peripherals, the offsets and addresses indicated in Table 4-3 are
of interest to us.

Table 4-3. Peripheral Offsets for the Raspberry Pi

Peripheral Offset Address Description C Offset Macro

Base 0x00000000 0x20000000 Starting address BCM2708_PERI_BASE

PADS_GPIO 0x00100000 0x20100000 PADS base PADS_GPIO_BASE

GPIO 00..27 0x0010002C 0x2010002C GPIO 00..27 pads PADS_GPIO_00_27

GPIO 28..45 0x00100030 0x20100030 GPIO 28..45 pads PADS_GPIO_28_45

GPIO 46..53 0x00100034 0x20100034 GPIO 46..53 pads PADS_GPIO_46_53

Clock 0x00101000 0x20101000 Clock registers CLK_BASE

GPIO 0x00200000 0x20200000 GPIO registers GPIO_BASE

GPPUD 0x00200025 0x20200025 Pull-up enable

GPPUDCLK0 0x00200026 0x20200026 Pull-up clock 0

GPPUDCLK1 0x00200027 0x20200027 Pull-up clock 1

PWM 0x0020C000 0x2020C000 PWM registers PWM_BASE