93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
/*
|
|
* 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 "hw/hw.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 regiters. */
|
|
#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"
|
|
#define AVR_USART(obj) \
|
|
OBJECT_CHECK(AVRUsartState, (obj), TYPE_AVR_USART)
|
|
|
|
typedef struct {
|
|
/* <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;
|
|
} AVRUsartState;
|
|
|
|
#endif /* HW_CHAR_AVR_USART_H */
|