diff --git a/sysmoOCTSIM/hal/include/hpl_usart_async.h b/sysmoOCTSIM/hal/include/hpl_usart_async.h
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+/**
+ * \file
+ *
+ * \brief USART related functionality declaration.
+ *
+ * Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Subject to your compliance with these terms, you may use Microchip
+ * software and any derivatives exclusively with Microchip products.
+ * It is your responsibility to comply with third party license terms applicable
+ * to your use of third party software (including open source software) that
+ * may accompany Microchip software.
+ *
+ * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES,
+ * WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE,
+ * INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY,
+ * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE
+ * LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL
+ * LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND WHATSOEVER RELATED TO THE
+ * SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED OF THE
+ * POSSIBILITY OR THE DAMAGES ARE FORESEEABLE.  TO THE FULLEST EXTENT
+ * ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY
+ * RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY,
+ * THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USART_ASYNC_H_INCLUDED
+#define _HPL_USART_ASYNC_H_INCLUDED
+
+/**
+ * \addtogroup HPL USART
+ *
+ * \section hpl_usart_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include "hpl_usart.h"
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief USART callback types
+ */
+enum _usart_async_callback_type { USART_ASYNC_BYTE_SENT, USART_ASYNC_RX_DONE, USART_ASYNC_TX_DONE, USART_ASYNC_ERROR };
+
+/**
+ * \brief USART device structure
+ *
+ * The USART device structure forward declaration.
+ */
+struct _usart_async_device;
+
+/**
+ * \brief USART interrupt callbacks
+ */
+struct _usart_async_callbacks {
+	void (*tx_byte_sent)(struct _usart_async_device *device);
+	void (*rx_done_cb)(struct _usart_async_device *device, uint8_t data);
+	void (*tx_done_cb)(struct _usart_async_device *device);
+	void (*error_cb)(struct _usart_async_device *device);
+};
+
+/**
+ * \brief USART descriptor device structure
+ */
+struct _usart_async_device {
+	struct _usart_async_callbacks usart_cb;
+	struct _irq_descriptor        irq;
+	void *                        hw;
+};
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize asynchronous USART
+ *
+ * This function does low level USART configuration.
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _usart_async_init(struct _usart_async_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize USART
+ *
+ * This function closes the given USART by disabling its clock.
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_deinit(struct _usart_async_device *const device);
+
+/**
+ * \brief Enable usart module
+ *
+ * This function will enable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable(struct _usart_async_device *const device);
+
+/**
+ * \brief Disable usart module
+ *
+ * This function will disable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_disable(struct _usart_async_device *const device);
+
+/**
+ * \brief Calculate baud rate register value
+ *
+ * \param[in] baud Required baud rate
+ * \param[in] clock_rate clock frequency
+ * \param[in] samples The number of samples
+ * \param[in] mode USART mode
+ * \param[in] fraction A fraction value
+ *
+ * \return Calculated baud rate register value
+ */
+uint16_t _usart_async_calculate_baud_rate(const uint32_t baud, const uint32_t clock_rate, const uint8_t samples,
+                                          const enum usart_baud_rate_mode mode, const uint8_t fraction);
+
+/**
+ * \brief Set baud rate
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] baud_rate A baud rate to set
+ */
+void _usart_async_set_baud_rate(struct _usart_async_device *const device, const uint32_t baud_rate);
+
+/**
+ * \brief Set data order
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] order A data order to set
+ */
+void _usart_async_set_data_order(struct _usart_async_device *const device, const enum usart_data_order order);
+
+/**
+ * \brief Set mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] mode A mode to set
+ */
+void _usart_async_set_mode(struct _usart_async_device *const device, const enum usart_mode mode);
+
+/**
+ * \brief Set parity
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] parity A parity to set
+ */
+void _usart_async_set_parity(struct _usart_async_device *const device, const enum usart_parity parity);
+
+/**
+ * \brief Set stop bits mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] stop_bits A stop bits mode to set
+ */
+void _usart_async_set_stop_bits(struct _usart_async_device *const device, const enum usart_stop_bits stop_bits);
+
+/**
+ * \brief Set character size
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] size A character size to set
+ */
+void _usart_async_set_character_size(struct _usart_async_device *const device, const enum usart_character_size size);
+
+/**
+ * \brief Retrieve usart status
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+uint32_t _usart_async_get_status(const struct _usart_async_device *const device);
+
+/**
+ * \brief Write a byte to the given USART instance
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] data Data to write
+ */
+void _usart_async_write_byte(struct _usart_async_device *const device, uint8_t data);
+
+/**
+ * \brief Check if USART is ready to send next byte
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return Status of the ready check.
+ * \retval true if the USART is ready to send next byte
+ * \retval false if the USART is not ready to send next byte
+ */
+bool _usart_async_is_byte_sent(const struct _usart_async_device *const device);
+
+/**
+ * \brief Set the state of flow control pins
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] state - A state of flow control pins to set
+ */
+void _usart_async_set_flow_control_state(struct _usart_async_device *const    device,
+                                         const union usart_flow_control_state state);
+
+/**
+ * \brief Retrieve the state of flow control pins
+ *
+ * This function retrieves the of flow control pins.
+ *
+ * \return USART_FLOW_CONTROL_STATE_UNAVAILABLE.
+ */
+union usart_flow_control_state _usart_async_get_flow_control_state(const struct _usart_async_device *const device);
+
+/**
+ * \brief Enable data register empty interrupt
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable_byte_sent_irq(struct _usart_async_device *const device);
+
+/**
+ * \brief Enable transmission complete interrupt
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable_tx_done_irq(struct _usart_async_device *const device);
+
+/**
+ * \brief Retrieve ordinal number of the given USART hardware instance
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return The ordinal number of the given USART hardware instance
+ */
+uint8_t _usart_async_get_hardware_index(const struct _usart_async_device *const device);
+
+/**
+ * \brief Enable/disable USART interrupt
+ *
+ * param[in] device The pointer to USART device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _usart_async_set_irq_state(struct _usart_async_device *const device, const enum _usart_async_callback_type type,
+                                const bool state);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_USART_ASYNC_H_INCLUDED */