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1 | 663e8e51 | ths | /*
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2 | 663e8e51 | ths | * QEMU EEPROM 93xx emulation
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3 | 663e8e51 | ths | *
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4 | 663e8e51 | ths | * Copyright (c) 2006-2007 Stefan Weil
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5 | 663e8e51 | ths | *
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6 | 663e8e51 | ths | * This program is free software; you can redistribute it and/or modify
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7 | 663e8e51 | ths | * it under the terms of the GNU General Public License as published by
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8 | 663e8e51 | ths | * the Free Software Foundation; either version 2 of the License, or
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9 | 663e8e51 | ths | * (at your option) any later version.
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10 | 663e8e51 | ths | *
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11 | 663e8e51 | ths | * This program is distributed in the hope that it will be useful,
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12 | 663e8e51 | ths | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | 663e8e51 | ths | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 | 663e8e51 | ths | * GNU General Public License for more details.
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15 | 663e8e51 | ths | *
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16 | 663e8e51 | ths | * You should have received a copy of the GNU General Public License
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17 | 663e8e51 | ths | * along with this program; if not, write to the Free Software
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18 | 663e8e51 | ths | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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19 | 663e8e51 | ths | */
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20 | 663e8e51 | ths | |
21 | 663e8e51 | ths | /* Emulation for serial EEPROMs:
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22 | 663e8e51 | ths | * NMC93C06 256-Bit (16 x 16)
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23 | 663e8e51 | ths | * NMC93C46 1024-Bit (64 x 16)
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24 | 663e8e51 | ths | * NMC93C56 2028 Bit (128 x 16)
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25 | 663e8e51 | ths | * NMC93C66 4096 Bit (256 x 16)
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26 | 663e8e51 | ths | * Compatible devices include FM93C46 and others.
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27 | 663e8e51 | ths | *
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28 | 663e8e51 | ths | * Other drivers use these interface functions:
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29 | 663e8e51 | ths | * eeprom93xx_new - add a new EEPROM (with 16, 64 or 256 words)
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30 | 663e8e51 | ths | * eeprom93xx_free - destroy EEPROM
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31 | 663e8e51 | ths | * eeprom93xx_read - read data from the EEPROM
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32 | 663e8e51 | ths | * eeprom93xx_write - write data to the EEPROM
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33 | 663e8e51 | ths | * eeprom93xx_data - get EEPROM data array for external manipulation
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34 | 663e8e51 | ths | *
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35 | 663e8e51 | ths | * Todo list:
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36 | 663e8e51 | ths | * - No emulation of EEPROM timings.
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37 | 663e8e51 | ths | */
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38 | 663e8e51 | ths | |
39 | 663e8e51 | ths | #include <assert.h> |
40 | 87ecb68b | pbrook | #include "hw.h" |
41 | 663e8e51 | ths | #include "eeprom93xx.h" |
42 | 663e8e51 | ths | |
43 | 663e8e51 | ths | /* Debug EEPROM emulation. */
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44 | 663e8e51 | ths | //~ #define DEBUG_EEPROM
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45 | 663e8e51 | ths | |
46 | 663e8e51 | ths | #ifdef DEBUG_EEPROM
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47 | 663e8e51 | ths | #define logout(fmt, args...) fprintf(stderr, "EEPROM\t%-24s" fmt, __func__, ##args) |
48 | 663e8e51 | ths | #else
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49 | 663e8e51 | ths | #define logout(fmt, args...) ((void)0) |
50 | 663e8e51 | ths | #endif
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51 | 663e8e51 | ths | |
52 | 7ab2589c | aurel32 | #define EEPROM_INSTANCE 0 |
53 | 7ab2589c | aurel32 | #define OLD_EEPROM_VERSION 20061112 |
54 | 7ab2589c | aurel32 | #define EEPROM_VERSION (OLD_EEPROM_VERSION + 1) |
55 | 663e8e51 | ths | |
56 | 663e8e51 | ths | #if 0
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57 | 663e8e51 | ths | typedef enum {
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58 | 663e8e51 | ths | eeprom_read = 0x80, /* read register xx */
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59 | 663e8e51 | ths | eeprom_write = 0x40, /* write register xx */
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60 | 663e8e51 | ths | eeprom_erase = 0xc0, /* erase register xx */
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61 | 663e8e51 | ths | eeprom_ewen = 0x30, /* erase / write enable */
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62 | 663e8e51 | ths | eeprom_ewds = 0x00, /* erase / write disable */
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63 | 663e8e51 | ths | eeprom_eral = 0x20, /* erase all registers */
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64 | 663e8e51 | ths | eeprom_wral = 0x10, /* write all registers */
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65 | 663e8e51 | ths | eeprom_amask = 0x0f,
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66 | 663e8e51 | ths | eeprom_imask = 0xf0
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67 | 663e8e51 | ths | } eeprom_instruction_t;
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68 | 663e8e51 | ths | #endif
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69 | 663e8e51 | ths | |
70 | 663e8e51 | ths | #ifdef DEBUG_EEPROM
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71 | 663e8e51 | ths | static const char *opstring[] = { |
72 | 663e8e51 | ths | "extended", "write", "read", "erase" |
73 | 663e8e51 | ths | }; |
74 | 663e8e51 | ths | #endif
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75 | 663e8e51 | ths | |
76 | 663e8e51 | ths | struct _eeprom_t {
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77 | 663e8e51 | ths | uint8_t tick; |
78 | 663e8e51 | ths | uint8_t address; |
79 | 663e8e51 | ths | uint8_t command; |
80 | 663e8e51 | ths | uint8_t writeable; |
81 | 663e8e51 | ths | |
82 | 663e8e51 | ths | uint8_t eecs; |
83 | 663e8e51 | ths | uint8_t eesk; |
84 | 663e8e51 | ths | uint8_t eedo; |
85 | 663e8e51 | ths | |
86 | 663e8e51 | ths | uint8_t addrbits; |
87 | 7ab2589c | aurel32 | uint16_t size; |
88 | 663e8e51 | ths | uint16_t data; |
89 | 663e8e51 | ths | uint16_t contents[0];
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90 | 663e8e51 | ths | }; |
91 | 663e8e51 | ths | |
92 | 663e8e51 | ths | /* Code for saving and restoring of EEPROM state. */
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93 | 663e8e51 | ths | |
94 | 663e8e51 | ths | static void eeprom_save(QEMUFile *f, void *opaque) |
95 | 663e8e51 | ths | { |
96 | 663e8e51 | ths | /* Save EEPROM data. */
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97 | 663e8e51 | ths | unsigned address;
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98 | 663e8e51 | ths | eeprom_t *eeprom = (eeprom_t *)opaque; |
99 | d4ae799c | aurel32 | |
100 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->tick); |
101 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->address); |
102 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->command); |
103 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->writeable); |
104 | d4ae799c | aurel32 | |
105 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->eecs); |
106 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->eesk); |
107 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->eedo); |
108 | d4ae799c | aurel32 | |
109 | d4ae799c | aurel32 | qemu_put_byte(f, eeprom->addrbits); |
110 | 7ab2589c | aurel32 | qemu_put_be16(f, eeprom->size); |
111 | 663e8e51 | ths | qemu_put_be16(f, eeprom->data); |
112 | 663e8e51 | ths | for (address = 0; address < eeprom->size; address++) { |
113 | 663e8e51 | ths | qemu_put_be16(f, eeprom->contents[address]); |
114 | 663e8e51 | ths | } |
115 | 663e8e51 | ths | } |
116 | 663e8e51 | ths | |
117 | 663e8e51 | ths | static int eeprom_load(QEMUFile *f, void *opaque, int version_id) |
118 | 663e8e51 | ths | { |
119 | 663e8e51 | ths | /* Load EEPROM data from saved data if version and EEPROM size
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120 | 663e8e51 | ths | of data and current EEPROM are identical. */
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121 | 663e8e51 | ths | eeprom_t *eeprom = (eeprom_t *)opaque; |
122 | 663e8e51 | ths | int result = -EINVAL;
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123 | 7ab2589c | aurel32 | if (version_id >= OLD_EEPROM_VERSION) {
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124 | 663e8e51 | ths | unsigned address;
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125 | 7ab2589c | aurel32 | int size = eeprom->size;
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126 | d4ae799c | aurel32 | |
127 | d4ae799c | aurel32 | eeprom->tick = qemu_get_byte(f); |
128 | d4ae799c | aurel32 | eeprom->address = qemu_get_byte(f); |
129 | d4ae799c | aurel32 | eeprom->command = qemu_get_byte(f); |
130 | d4ae799c | aurel32 | eeprom->writeable = qemu_get_byte(f); |
131 | d4ae799c | aurel32 | |
132 | d4ae799c | aurel32 | eeprom->eecs = qemu_get_byte(f); |
133 | d4ae799c | aurel32 | eeprom->eesk = qemu_get_byte(f); |
134 | d4ae799c | aurel32 | eeprom->eedo = qemu_get_byte(f); |
135 | d4ae799c | aurel32 | |
136 | d4ae799c | aurel32 | eeprom->addrbits = qemu_get_byte(f); |
137 | 7ab2589c | aurel32 | if (version_id == OLD_EEPROM_VERSION) {
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138 | 7ab2589c | aurel32 | eeprom->size = qemu_get_byte(f); |
139 | 7ab2589c | aurel32 | qemu_get_byte(f); |
140 | 7ab2589c | aurel32 | } else {
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141 | 7ab2589c | aurel32 | eeprom->size = qemu_get_be16(f); |
142 | 7ab2589c | aurel32 | } |
143 | d4ae799c | aurel32 | |
144 | 663e8e51 | ths | if (eeprom->size == size) {
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145 | 663e8e51 | ths | eeprom->data = qemu_get_be16(f); |
146 | 663e8e51 | ths | for (address = 0; address < eeprom->size; address++) { |
147 | 663e8e51 | ths | eeprom->contents[address] = qemu_get_be16(f); |
148 | 663e8e51 | ths | } |
149 | 663e8e51 | ths | result = 0;
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150 | 663e8e51 | ths | } |
151 | 663e8e51 | ths | } |
152 | 663e8e51 | ths | return result;
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153 | 663e8e51 | ths | } |
154 | 663e8e51 | ths | |
155 | 663e8e51 | ths | void eeprom93xx_write(eeprom_t *eeprom, int eecs, int eesk, int eedi) |
156 | 663e8e51 | ths | { |
157 | 663e8e51 | ths | uint8_t tick = eeprom->tick; |
158 | 663e8e51 | ths | uint8_t eedo = eeprom->eedo; |
159 | 663e8e51 | ths | uint16_t address = eeprom->address; |
160 | 663e8e51 | ths | uint8_t command = eeprom->command; |
161 | 663e8e51 | ths | |
162 | 663e8e51 | ths | logout("CS=%u SK=%u DI=%u DO=%u, tick = %u\n",
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163 | 663e8e51 | ths | eecs, eesk, eedi, eedo, tick); |
164 | 663e8e51 | ths | |
165 | 663e8e51 | ths | if (! eeprom->eecs && eecs) {
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166 | 663e8e51 | ths | /* Start chip select cycle. */
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167 | 663e8e51 | ths | logout("Cycle start, waiting for 1st start bit (0)\n");
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168 | 663e8e51 | ths | tick = 0;
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169 | 663e8e51 | ths | command = 0x0;
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170 | 663e8e51 | ths | address = 0x0;
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171 | 663e8e51 | ths | } else if (eeprom->eecs && ! eecs) { |
172 | 663e8e51 | ths | /* End chip select cycle. This triggers write / erase. */
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173 | 663e8e51 | ths | if (eeprom->writeable) {
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174 | 663e8e51 | ths | uint8_t subcommand = address >> (eeprom->addrbits - 2);
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175 | 663e8e51 | ths | if (command == 0 && subcommand == 2) { |
176 | 663e8e51 | ths | /* Erase all. */
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177 | 663e8e51 | ths | for (address = 0; address < eeprom->size; address++) { |
178 | 663e8e51 | ths | eeprom->contents[address] = 0xffff;
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179 | 663e8e51 | ths | } |
180 | 663e8e51 | ths | } else if (command == 3) { |
181 | 663e8e51 | ths | /* Erase word. */
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182 | 663e8e51 | ths | eeprom->contents[address] = 0xffff;
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183 | 663e8e51 | ths | } else if (tick >= 2 + 2 + eeprom->addrbits + 16) { |
184 | 663e8e51 | ths | if (command == 1) { |
185 | 663e8e51 | ths | /* Write word. */
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186 | 663e8e51 | ths | eeprom->contents[address] &= eeprom->data; |
187 | 663e8e51 | ths | } else if (command == 0 && subcommand == 1) { |
188 | 663e8e51 | ths | /* Write all. */
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189 | 663e8e51 | ths | for (address = 0; address < eeprom->size; address++) { |
190 | 663e8e51 | ths | eeprom->contents[address] &= eeprom->data; |
191 | 663e8e51 | ths | } |
192 | 663e8e51 | ths | } |
193 | 663e8e51 | ths | } |
194 | 663e8e51 | ths | } |
195 | 663e8e51 | ths | /* Output DO is tristate, read results in 1. */
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196 | 663e8e51 | ths | eedo = 1;
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197 | 663e8e51 | ths | } else if (eecs && ! eeprom->eesk && eesk) { |
198 | 663e8e51 | ths | /* Raising edge of clock shifts data in. */
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199 | 663e8e51 | ths | if (tick == 0) { |
200 | 663e8e51 | ths | /* Wait for 1st start bit. */
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201 | 663e8e51 | ths | if (eedi == 0) { |
202 | 663e8e51 | ths | logout("Got correct 1st start bit, waiting for 2nd start bit (1)\n");
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203 | 663e8e51 | ths | tick++; |
204 | 663e8e51 | ths | } else {
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205 | 663e8e51 | ths | logout("wrong 1st start bit (is 1, should be 0)\n");
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206 | 663e8e51 | ths | tick = 2;
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207 | 663e8e51 | ths | //~ assert(!"wrong start bit");
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208 | 663e8e51 | ths | } |
209 | 663e8e51 | ths | } else if (tick == 1) { |
210 | 663e8e51 | ths | /* Wait for 2nd start bit. */
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211 | 663e8e51 | ths | if (eedi != 0) { |
212 | 663e8e51 | ths | logout("Got correct 2nd start bit, getting command + address\n");
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213 | 663e8e51 | ths | tick++; |
214 | 663e8e51 | ths | } else {
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215 | 663e8e51 | ths | logout("1st start bit is longer than needed\n");
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216 | 663e8e51 | ths | } |
217 | 663e8e51 | ths | } else if (tick < 2 + 2) { |
218 | 663e8e51 | ths | /* Got 2 start bits, transfer 2 opcode bits. */
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219 | 663e8e51 | ths | tick++; |
220 | 663e8e51 | ths | command <<= 1;
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221 | 663e8e51 | ths | if (eedi) {
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222 | 663e8e51 | ths | command += 1;
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223 | 663e8e51 | ths | } |
224 | 663e8e51 | ths | } else if (tick < 2 + 2 + eeprom->addrbits) { |
225 | 663e8e51 | ths | /* Got 2 start bits and 2 opcode bits, transfer all address bits. */
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226 | 663e8e51 | ths | tick++; |
227 | 663e8e51 | ths | address = ((address << 1) | eedi);
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228 | 663e8e51 | ths | if (tick == 2 + 2 + eeprom->addrbits) { |
229 | 663e8e51 | ths | logout("%s command, address = 0x%02x (value 0x%04x)\n",
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230 | 663e8e51 | ths | opstring[command], address, eeprom->contents[address]); |
231 | 663e8e51 | ths | if (command == 2) { |
232 | 663e8e51 | ths | eedo = 0;
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233 | 663e8e51 | ths | } |
234 | 663e8e51 | ths | address = address % eeprom->size; |
235 | 663e8e51 | ths | if (command == 0) { |
236 | 663e8e51 | ths | /* Command code in upper 2 bits of address. */
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237 | 663e8e51 | ths | switch (address >> (eeprom->addrbits - 2)) { |
238 | 663e8e51 | ths | case 0: |
239 | 663e8e51 | ths | logout("write disable command\n");
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240 | 663e8e51 | ths | eeprom->writeable = 0;
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241 | 663e8e51 | ths | break;
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242 | 663e8e51 | ths | case 1: |
243 | 663e8e51 | ths | logout("write all command\n");
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244 | 663e8e51 | ths | break;
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245 | 663e8e51 | ths | case 2: |
246 | 663e8e51 | ths | logout("erase all command\n");
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247 | 663e8e51 | ths | break;
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248 | 663e8e51 | ths | case 3: |
249 | 663e8e51 | ths | logout("write enable command\n");
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250 | 663e8e51 | ths | eeprom->writeable = 1;
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251 | 663e8e51 | ths | break;
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252 | 663e8e51 | ths | } |
253 | 663e8e51 | ths | } else {
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254 | 663e8e51 | ths | /* Read, write or erase word. */
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255 | 663e8e51 | ths | eeprom->data = eeprom->contents[address]; |
256 | 663e8e51 | ths | } |
257 | 663e8e51 | ths | } |
258 | 663e8e51 | ths | } else if (tick < 2 + 2 + eeprom->addrbits + 16) { |
259 | 663e8e51 | ths | /* Transfer 16 data bits. */
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260 | 663e8e51 | ths | tick++; |
261 | 663e8e51 | ths | if (command == 2) { |
262 | 663e8e51 | ths | /* Read word. */
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263 | 663e8e51 | ths | eedo = ((eeprom->data & 0x8000) != 0); |
264 | 663e8e51 | ths | } |
265 | 663e8e51 | ths | eeprom->data <<= 1;
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266 | 663e8e51 | ths | eeprom->data += eedi; |
267 | 663e8e51 | ths | } else {
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268 | 663e8e51 | ths | logout("additional unneeded tick, not processed\n");
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269 | 663e8e51 | ths | } |
270 | 663e8e51 | ths | } |
271 | 663e8e51 | ths | /* Save status of EEPROM. */
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272 | 663e8e51 | ths | eeprom->tick = tick; |
273 | 663e8e51 | ths | eeprom->eecs = eecs; |
274 | 663e8e51 | ths | eeprom->eesk = eesk; |
275 | 663e8e51 | ths | eeprom->eedo = eedo; |
276 | 663e8e51 | ths | eeprom->address = address; |
277 | 663e8e51 | ths | eeprom->command = command; |
278 | 663e8e51 | ths | } |
279 | 663e8e51 | ths | |
280 | 663e8e51 | ths | uint16_t eeprom93xx_read(eeprom_t *eeprom) |
281 | 663e8e51 | ths | { |
282 | 663e8e51 | ths | /* Return status of pin DO (0 or 1). */
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283 | 663e8e51 | ths | logout("CS=%u DO=%u\n", eeprom->eecs, eeprom->eedo);
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284 | 663e8e51 | ths | return (eeprom->eedo);
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285 | 663e8e51 | ths | } |
286 | 663e8e51 | ths | |
287 | 663e8e51 | ths | #if 0
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288 | 663e8e51 | ths | void eeprom93xx_reset(eeprom_t *eeprom)
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289 | 663e8e51 | ths | {
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290 | 663e8e51 | ths | /* prepare eeprom */
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291 | 663e8e51 | ths | logout("eeprom = 0x%p\n", eeprom);
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292 | 663e8e51 | ths | eeprom->tick = 0;
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293 | 663e8e51 | ths | eeprom->command = 0;
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294 | 663e8e51 | ths | }
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295 | 663e8e51 | ths | #endif
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296 | 663e8e51 | ths | |
297 | 663e8e51 | ths | eeprom_t *eeprom93xx_new(uint16_t nwords) |
298 | 663e8e51 | ths | { |
299 | 663e8e51 | ths | /* Add a new EEPROM (with 16, 64 or 256 words). */
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300 | 663e8e51 | ths | eeprom_t *eeprom; |
301 | 663e8e51 | ths | uint8_t addrbits; |
302 | 663e8e51 | ths | |
303 | 663e8e51 | ths | switch (nwords) {
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304 | 663e8e51 | ths | case 16: |
305 | 663e8e51 | ths | case 64: |
306 | 663e8e51 | ths | addrbits = 6;
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307 | 663e8e51 | ths | break;
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308 | 663e8e51 | ths | case 128: |
309 | 663e8e51 | ths | case 256: |
310 | 663e8e51 | ths | addrbits = 8;
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311 | 663e8e51 | ths | break;
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312 | 663e8e51 | ths | default:
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313 | 663e8e51 | ths | assert(!"Unsupported EEPROM size, fallback to 64 words!");
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314 | 663e8e51 | ths | nwords = 64;
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315 | 663e8e51 | ths | addrbits = 6;
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316 | 663e8e51 | ths | } |
317 | 663e8e51 | ths | |
318 | 663e8e51 | ths | eeprom = (eeprom_t *)qemu_mallocz(sizeof(*eeprom) + nwords * 2); |
319 | 663e8e51 | ths | eeprom->size = nwords; |
320 | 663e8e51 | ths | eeprom->addrbits = addrbits; |
321 | 663e8e51 | ths | /* Output DO is tristate, read results in 1. */
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322 | 663e8e51 | ths | eeprom->eedo = 1;
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323 | 663e8e51 | ths | logout("eeprom = 0x%p, nwords = %u\n", eeprom, nwords);
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324 | 7ab2589c | aurel32 | register_savevm("eeprom", EEPROM_INSTANCE, EEPROM_VERSION,
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325 | 663e8e51 | ths | eeprom_save, eeprom_load, eeprom); |
326 | 663e8e51 | ths | return eeprom;
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327 | 663e8e51 | ths | } |
328 | 663e8e51 | ths | |
329 | 663e8e51 | ths | void eeprom93xx_free(eeprom_t *eeprom)
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330 | 663e8e51 | ths | { |
331 | 663e8e51 | ths | /* Destroy EEPROM. */
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332 | 663e8e51 | ths | logout("eeprom = 0x%p\n", eeprom);
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333 | 663e8e51 | ths | qemu_free(eeprom); |
334 | 663e8e51 | ths | } |
335 | 663e8e51 | ths | |
336 | 663e8e51 | ths | uint16_t *eeprom93xx_data(eeprom_t *eeprom) |
337 | 663e8e51 | ths | { |
338 | 663e8e51 | ths | /* Get EEPROM data array. */
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339 | 663e8e51 | ths | return &eeprom->contents[0]; |
340 | 663e8e51 | ths | } |
341 | 663e8e51 | ths | |
342 | 663e8e51 | ths | /* eof */ |