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/*
* AVR USART
*
* Copyright (c) 2018 University of Kent
* Author: Sarah Harris
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>
*/
#ifndef HW_CHAR_AVR_USART_H
#define HW_CHAR_AVR_USART_H
#include "hw/sysbus.h"
#include "chardev/char-fe.h"
#include "qom/object.h"
/* Offsets of registers. */
#define USART_DR 0x06
#define USART_CSRA 0x00
#define USART_CSRB 0x01
#define USART_CSRC 0x02
#define USART_BRRH 0x05
#define USART_BRRL 0x04
/* Relevant bits in registers. */
#define USART_CSRA_RXC (1 << 7)
#define USART_CSRA_TXC (1 << 6)
#define USART_CSRA_DRE (1 << 5)
#define USART_CSRA_MPCM (1 << 0)
#define USART_CSRB_RXCIE (1 << 7)
#define USART_CSRB_TXCIE (1 << 6)
#define USART_CSRB_DREIE (1 << 5)
#define USART_CSRB_RXEN (1 << 4)
#define USART_CSRB_TXEN (1 << 3)
#define USART_CSRB_CSZ2 (1 << 2)
#define USART_CSRB_RXB8 (1 << 1)
#define USART_CSRB_TXB8 (1 << 0)
#define USART_CSRC_MSEL1 (1 << 7)
#define USART_CSRC_MSEL0 (1 << 6)
#define USART_CSRC_PM1 (1 << 5)
#define USART_CSRC_PM0 (1 << 4)
#define USART_CSRC_CSZ1 (1 << 2)
#define USART_CSRC_CSZ0 (1 << 1)
#define TYPE_AVR_USART "avr-usart"
OBJECT_DECLARE_SIMPLE_TYPE(AVRUsartState, AVR_USART)
struct AVRUsartState {
/* <private> */
SysBusDevice parent_obj;
/* <public> */
MemoryRegion mmio;
CharBackend chr;
bool enabled;
uint8_t data;
bool data_valid;
uint8_t char_mask;
/* Control and Status Registers */
uint8_t csra;
uint8_t csrb;
uint8_t csrc;
/* Baud Rate Registers (low/high byte) */
uint8_t brrh;
uint8_t brrl;
/* Receive Complete */
qemu_irq rxc_irq;
/* Transmit Complete */
qemu_irq txc_irq;
/* Data Register Empty */
qemu_irq dre_irq;
};
#endif /* HW_CHAR_AVR_USART_H */