Lattice Semiconductor

ispPAC-POWR604 Data Sheet

2-10

1

Table 2-1 shows all possible comparator trip point voltage settings. The internal resistive divider allows ranges for

1.2V, 1.8V, 2.5V, 3.3V and 5.0V. There are 192 available voltages, ranging from 1.036V to 5.723V. In addition to the

192 voltage monitor trip points, the user can add additional resistors outside the device to divide down the voltage

and achieve virtually any voltage trip point. This allows the capability to monitor higher voltages such and 12V, 15V,

24V, etc. Voltage monitor trip points are set in the graphical user interface of the PAC-Designer software by simple

pull-down menus. The user simply selects the given range and corresponding trip point value. Attenuation and ref-

erence values are set internally using E

Figure 2-2 shows a single comparator, the attenuation network and reference used to program the monitor trip

points. Each of the six comparators are independently set in the same way.

Theory Of Operation

The ispPAC-POWR604 incorporates programmable voltage monitors along with digital inputs and outputs. The

eight macrocell PLD inputs are from the six voltage monitors and four digital inputs. There are two embedded pro-

grammable timers that interface with the PLD, along with an internal programmable oscillator.

The six independently programmable voltage monitors each have 192 programmable trip points.

Figure 2-2 shows a simplified schematic representation of one of these monitors.

1.2 low

1.2 high

1.5 low

1.5 high

1.8 low

1.8 high

2.5 low

2.5 high

3.3 low

3.3 high

5.0 low

5.0 high

1.036

1.202

1.291

1.502

1.549

1.801

2.153

2.500

2.842

3.297

4.299

4.991

1.046

1.213

1.303

1.516

1.564

1.818

2.173

2.524

2.869

3.328

4.340

5.038

1.056

1.225

1.316

1.531

1.579

1.836

2.195

2.549

2.897

3.361

4.383

5.088

1.066

1.237

1.329

1.546

1.595

1.854

2.216

2.574

2.926

3.394

4.426

5.138

1.076

1.249

1.341

1.560

1.609

1.871

2.237

2.597

2.952

3.425

4.466

5.185

1.087

1.261

1.354

1.575

1.625

1.889

2.258

2.622

2.981

3.458

4.509

5.235

1.096

1.272

1.366

1.590

1.639

1.906

2.279

2.646

3.008

3.489

4.550

5.282

1.107

1.284

1.379

1.605

1.655

1.924

2.300

2.671

3.036

3.522

4.593

5.332

1.117

1.295

1.391

1.619

1.669

1.941

2.320

2.694

3.063

3.553

4.633

5.379

1.127

1.307

1.404

1.634

1.685

1.959

2.342

2.719

3.091

3.586

4.676

5.429

1.137

1.319

1.417

1.649

1.700

1.977

2.363

2.744

3.120

3.619

4.719

5.479

1.147

1.331

1.429

1.663

1.715

1.994

2.384

2.768

3.147

3.650

4.760

5.526

1.157

1.343

1.442

1.678

1.730

2.012

2.405

2.793

3.175

3.683

4.803

5.576

1.168

1.355

1.455

1.693

1.746

2.030

2.427

2.818

3.203

3.716

4.846

5.626

1.178

1.366

1.467

1.707

1.761

2.047

2.447

2.841

3.230

3.747

4.886

5.673

1.188

1.378

1.480

1.722

1.776

2.065

2.469

2.866

3.259

3.780

4.929

5.723

1.All possible comparator trip voltages using internal attenuation settings.