1 files changed, 10 insertions, 7 deletions
diff --git a/doc/langref/packed_struct_mmio.zig b/doc/langref/packed_struct_mmio.zig
index 79236a76ea..18b57f83b2 100644
--- a/doc/langref/packed_struct_mmio.zig
+++ b/doc/langref/packed_struct_mmio.zig
@@ -1,16 +1,19 @@
-pub const GPIORegister = packed struct(u8) {
+pub const GpioRegister = packed struct(u8) {
     GPIO0: bool,
     GPIO1: bool,
     GPIO2: bool,
     GPIO3: bool,
-    _reserved: u4 = 0,
+    reserved: u4 = 0,
 };
 
-/// Write a new state to the memory-mapped IO.
-pub fn writeToGPIO(new_states: GPIORegister) void {
-    const gpio_register_address = 0x0123;
-    const raw_ptr: *align(1) volatile GPIORegister = @ptrFromInt(gpio_register_address);
-    raw_ptr.* = new_states;
+const gpio: *volatile GpioRegister = @ptrFromInt(0x0123);
+
+pub fn writeToGpio(new_states: GpioRegister) void {
+    // Example of what not to do:
+    // BAD! gpio.GPIO0 = true; BAD!
+
+    // Instead, do this:
+    gpio.* = new_states;
 }
 
 // syntax