VirtualBox

source: vbox/trunk/src/VBox/Devices/Network/DevEEPROM.h@ 103914

Last change on this file since 103914 was 98103, checked in by vboxsync, 21 months ago

Copyright year updates by scm.

  • Property svn:eol-style set to native
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File size: 4.4 KB
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1/* $Id: DevEEPROM.h 98103 2023-01-17 14:15:46Z vboxsync $ */
2/** @file
3 * DevEEPROM - Microwire-compatible 64x16-bit 93C46 EEPROM Emulation, Header.
4 */
5
6/*
7 * Copyright (C) 2007-2023 Oracle and/or its affiliates.
8 *
9 * This file is part of VirtualBox base platform packages, as
10 * available from https://www.virtualbox.org.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation, in version 3 of the
15 * License.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, see <https://www.gnu.org/licenses>.
24 *
25 * SPDX-License-Identifier: GPL-3.0-only
26 */
27
28#ifndef VBOX_INCLUDED_SRC_Network_DevEEPROM_h
29#define VBOX_INCLUDED_SRC_Network_DevEEPROM_h
30#ifndef RT_WITHOUT_PRAGMA_ONCE
31# pragma once
32#endif
33
34#include <iprt/types.h>
35
36/** The current Saved state version. */
37#define EEPROM93C46_SAVEDSTATE_VERSION 1
38
39/**
40 * 93C46-compatible EEPROM device emulation.
41 *
42 * @remarks This class is intended to be used in device
43 * emulation which imposes some restrictions if the
44 * device supports GC execution. This is why it is a
45 * plain-old-data structure.
46 */
47struct EEPROM93C46
48{
49 /** General definitions */
50 enum {
51 /** Size of EEPROM in words */
52 SIZE = 64,
53 /** Number of bits per word */
54 WORD_SIZE = 16,
55 /** Number of address bits */
56 ADDR_SIZE = 6,
57 /** Number of bits in opcode */
58 OPCODE_SIZE = 2,
59 /** The most significant bit mask in data word */
60 DATA_MSB = 1<<(WORD_SIZE-1),
61 /** Address mask */
62 ADDR_MASK = (1<<ADDR_SIZE)-1,
63 /** The most significant bit mask in op+addr bit sequence */
64 OPADDR_MSB = 1<<(OPCODE_SIZE+ADDR_SIZE-1)
65 };
66
67 enum OP {
68 OP_READ,
69 OP_WRITE,
70 OP_WRITE_ALL,
71 OP_DECODE,
72 OP_32BIT_HACK = 0x7fffffff
73 };
74
75 /**
76 * Names of signal wires
77 */
78 enum Wires {
79 WIRES_SK=0x1, ///< Clock
80 WIRES_CS=0x2, ///< Chip Select
81 WIRES_DI=0x4, ///< Data In
82 WIRES_DO=0x8 ///< Data Out
83 };
84
85
86 /** @todo save and load methods */
87 void save(PCPDMDEVHLPR3 pHlp, PSSMHANDLE pSSM);
88 int load(PCPDMDEVHLPR3 pHlp, PSSMHANDLE pSSM);
89
90 /** Actual content of EEPROM */
91 uint16_t m_au16Data[SIZE];
92
93 /** current state.
94 *
95 * EEPROM operates as a simple state machine. Events are primarily
96 * triggered at positive edge of clock signal (SK). Refer to the
97 * timing diagrams of 93C46 to get better understanding.
98 */
99 enum State {
100 /** Initial state. Waiting for start condition (CS, SK, DI high). */
101 STANDBY,
102 /** Reading data in, shifting in the bits into 'word'. */
103 READING_DI,
104 /** Writing data out, shifting out the bits from 'word'. */
105 WRITING_DO,
106 /** Waiting for CS=0 to indicate we are busy (DO=0). */
107 WAITING_CS_FALL,
108 /** Waiting for CS=1 to indicate we are ready (DO=1). */
109 WAITING_CS_RISE,
110 /** Make this enum 4-byte */
111 STATE_MAKE_32BIT_HACK = 0x7fffffff
112 } m_eState;
113 /** setting writeEnable to false prevents write and erase operations */
114 bool m_fWriteEnabled;
115 uint8_t Alignment1;
116 /** intermediate storage */
117 uint16_t m_u16Word;
118 /** currently processed bit in 'word' */
119 uint16_t m_u16Mask;
120 /** decoded address */
121 uint16_t m_u16Addr;
122 /** Data Out, Data In, Chip Select, Clock */
123 uint32_t m_u32InternalWires;
124
125 /** Current opcode decoder. When no operation has been decoded yet
126 * it is set to OP_DECODE.
127 */
128 OP m_eOp;
129#if HC_ARCH_BITS == 64
130 uint32_t Alignment2;
131#endif
132
133#ifdef IN_RING3
134 uint32_t read();
135 void write(uint32_t u32Wires);
136 bool readWord(uint32_t u32Addr, uint16_t *pu16Value);
137
138 void init(const uint16_t *pu16Initial = 0);
139
140 // Operation handlers
141 State opDecode();
142 State opRead();
143 State opWrite();
144 State opWriteAll();
145
146 /** Helper method to implement write protection */
147 void storeWord(uint32_t u32Addr, uint16_t u16Value);
148#endif /* IN_RING3 */
149};
150
151#endif /* !VBOX_INCLUDED_SRC_Network_DevEEPROM_h */
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