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+# ral-registers
+
+[![Version](https://img.shields.io/crates/v/ral-registers.svg)](https://crates.io/crates/ral-registers)
+[![Documentation](https://docs.rs/ral-registers/badge.svg)](https://docs.rs/ral-registers)
+![CI](https://github.com/adamgreig/ral-registers/workflows/CI/badge.svg)
+![License](https://img.shields.io/crates/l/ral-registers.svg)
+
+This crate contains an MMIO abstraction that uses macros to read, modify,
+and write fields in registers.
+
+For example, several fields on a register can be updated (without changing the
+other fields) using:
+
+```rust
+// Modify some fields on GPIOA.MODER without changing others.
+modify_reg!(gpio, GPIOA, MODER, MODER1: Input, MODER2: Output, MODER3: Input);
+
+// Check a condition on a field.
+while read_reg!(gpio, GPIOA, IDR, IDR3 == High) {}
+
+// Read and write the entire register word value.
+let port = read_reg!(gpio, GPIOA, IDR);
+write_reg!(gpio, GPIOA, port);
+```
+
+This crate contains register code originally written in
+[stm32ral](https://github.com/adamgreig/stm32ral), extracted
+for easier use in other projects.
+
+## Licence
+
+Licensed under either of
+
+* Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
+  http://www.apache.org/licenses/LICENSE-2.0)
+* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+## Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.