HP LaserJet Enterprise 500 Maintenance Manual - Page 229

Engine Controller

Page 229 highlights

Engine Controller Engine Controller The engine controller (EC) consists of four main elements: • 80C166 Microcontroller • 128KB 5.0V-only FLASH program memory, organized as 64K x 16 bits. This memory is not expandable. • MECA (Mechanism Engine Control ASIC) • Analog drive circuitry 80C166 Microprocessor The Siemens® SAB 80C166 is a high-integration microcontroller. It has many features that suit it extremely well to real-time control applications. This controller and the MECA ASIC provide the functionality of three separate processors used in earlier controller board architectures. In this manual, the 80C166 is referred to as either the EC or the 166. Bus Configuration The 166 bus is configured for 18-bit address, 16-bit data, non-multiplexed and segmented operation. The flash memory runs with zero wait states. An external PAL is used for address decoding. Power Reduction The 166 chip has two power reduction modes: idle and Energy Star. Idle mode is not used. In Energy Star® mode, +48V and all motors are deenergized, but the 166 operates as normal. EC Flash Memory The EC stores all boot code, program code, and tables in its own local flash memory. This flash is organized as 64Kx16 bits and uses the same technology as the DC flash: it is +5.0V-only and is rated for a minimum of 100,000 write/erase cycles. EC memory is fixed; it is soldered to the controller board. Its contents can be updated through the DC (through the serial or parallel ports). At run time, the EC also stores tables in shared DRAM, which is accessed through the Cajun bus. MECA ASIC The 166 uses numerous counters, PWM generators, and FIFOs in the MECA to control many printer motor functions. The MECA is a custom gate array, specifically designed to drive this system. Analog Drive Circuitry The analog drive circuits convert +48 volts and +8.5 volts into the power used to drive the motors and hammers in the printer. Sensors are used to monitor the operation and status of critical components within the printer. 229

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356

Engine Controller
229
Engine Controller
The engine controller (EC) consists of four main elements:
80C166 Microcontroller
128KB 5.0V-only FLASH program memory, organized as 64K x 16 bits.
This memory is not expandable.
MECA (Mechanism Engine Control ASIC)
Analog drive circuitry
80C166 Microprocessor
The Siemens® SAB 80C166 is a high-integration microcontroller. It has many
features that suit it extremely well to real-time control applications. This
controller and the MECA ASIC provide the functionality of three separate
processors used in earlier controller board architectures. In this manual, the
80C166 is referred to as either the EC or the 166.
Bus Configuration
The 166 bus is configured for 18-bit address, 16-bit data, non-multiplexed and
segmented operation. The flash memory runs with zero wait states. An
external PAL is used for address decoding.
Power Reduction
The 166 chip has two power reduction modes: idle and Energy Star. Idle
mode is not used. In Energy Star® mode, +48V and all motors are de-
energized, but the 166 operates as normal.
EC Flash Memory
The EC stores all boot code, program code, and tables in its own local flash
memory. This flash is organized as 64Kx16 bits and uses the same
technology as the DC flash: it is +5.0V-only and is rated for a minimum of
100,000 write/erase cycles. EC memory is fixed; it is soldered to the controller
board. Its contents can be updated through the DC (through the serial or
parallel ports). At run time, the EC also stores tables in shared DRAM, which
is accessed through the Cajun bus.
MECA ASIC
The 166 uses numerous counters, PWM generators, and FIFOs in the MECA
to control many printer motor functions. The MECA is a custom gate array,
specifically designed to drive this system.
Analog Drive Circuitry
The analog drive circuits convert +48 volts and +8.5 volts into the power used
to drive the motors and hammers in the printer. Sensors are used to monitor
the operation and status of critical components within the printer.