18

Frame Capture

This is a fast way to download a full array of pixel values

from a single frame. This mode disables navigation and

overwrites any downloaded firmware. A hardware reset is

required to restore navigation, and the firmware must be

reloaded.

To trigger the capture, write to the Frame_Capture reg-

ister. The next available complete 1 frame image will be

stored to memory. The data are retrieved by reading the

Pixel_Burst register once using the normal read method,

after which the remaining bytes are clocked out by driving

SCLK at the normal rate. If the Pixel_Burst register is read

before the data is ready, it will return all zeros.

NOTE: Manual reset and SROM download are needed after

Frame Capture to restore navigation for motion reading.

Procedure of Frame Capture:

1. The sensor should have powered up and reset correctly.

2. Enable laser by setting Forced_Disable bit (Bit-0) of

LASER_CTRL0 register to 0.

3. Disable rest modes by setting REST_EN = 0 (Bit-5) of

Configuration_II register

4. Write 0x93 to Frame_Capture register.

5. Write 0xc5 to Frame_Capture register.

6. Wait for 20ms

7. Check for first pixel by reading bit zero of Motion

register. If =1, first pixel is available.

8. Continue read from Pixel_Burst register until all 484

pixels are transferred.

9. Continue step 4-8 to capture another frame.

Figure 17. Pixel Address Map (surface referenced)

RB

LB

Top Xray View of Mouse

Positive X

Positive Y

0

22

44

66

88

110

132

154

176

198

242

264

286

308

330

352

374

396

418

440

462

1

23

45

67

89

111

133

155

177

199

243

265

287

309

331

353

375

397

419

441

463

2

24

etc.

459

481

20

42

64

86

108

130

152

174

196

218

262

284

306

328

350

372 394

416

438

460

482

21

43

65

87

109

131

153

175

197

219

263

285

307

329

351

373 395

417

439

461

483

Expanded view of the surface as viewed

through the lens

Last output

First output

1

8

9

16

220

221

240

241

PixArt Imaging Inc.

Track-on-Glass Laser Sensor

All rights strictly reserved any portion in this paper shall not be reproduced, copied or transformed to any other forms without permission.

PixArt Imaging Inc.