CIRCC datasheet(14/70 Pages) SMSC

14 / 70 page

Bit Rate Divider

The Transmit and Receive Bit Rate Divider

stream for the CIrCC SCE. The divider is eight

bits wide.

The input clock to the Bit Rate Divider is 100kHz

(Carrier Frequency Divider input clock

÷ 16).

The relationship between the Bit Rate Divider

(BRD) and the Bit Rate (Fb) is as follows:

BRD = (.1MHz/Fb) - 1

For example, program the Bit Rate Divider with

55 ('37'Hex) for a .562ms Remote Control bit cell

like for the NEC remote control frame format: Fb

= 1.786kHz.

This is ~.5% accuracy. Table 9

contains

representative

BRD

vs.

Bit

Rate

relationships. The Bit Rate range is 100kHz to

390.625Hz.

It is important to note that the bit rate as

determined by the SCE CIR Bit Rate Divider

for

any

given

consumer

remote

control

modulation scheme. For example, to support the

NEC PPM remote control message frame format

in the CIrCC, the value programmed in the SCE

CIR Bit Rate register must be one half of the

signaling rate for an NEC PPM “0” (see Figure

5).

Table 9 - Representative Bit Rates

BRD

003

007

011

015

019

023

027

031

035

039

043

047

051

055

059

063

Fb (kHz)

25.000

12.500

8.333

6.250

5.000

4.167

3.571

3.125

2.778

2.500

2.273

2.083

1.923

1.786

1.667

1.563

BRD

067

071

075

079

083

087

091

095

099

103

107

111

115

119

123

127

Fb (kHz)

1.471

1.389

1.316

1.250

1.190

1.136

1.087

1.042

1.000

0.962

0.926

0.893

0.862

0.833

0.806

0.781

BRD

131

135

139

143

147

151

155

159

163

167

171

175

179

183

187

191

Fb (kHz)

0.758

0.735

0.714

0.694

0.676

0.658

0.641

0.625

0.610

0.595

0.581

0.568

0.556

0.543

0.532

0.521

BRD

195

199

203

207

211

215

219

223

227

231

235

239

243

247

251

255

Fb (kHz)

0.510

0.500

0.490

0.481

0.472

0.463

0.455

0.446

0.439

0.431

0.424

0.417

0.410

0.403

0.397

0.391

CIRCC Datasheet(PDF) 14 Page - SMSC Corporation

CIRCC Datasheet(HTML) 14 Page - SMSC Corporation

Html Pages

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

Datasheet Download

Link URL