ST7DALI datasheet(74/141 Pages) STMICROELECTRONICS

Teilenummer	ST7DALI

Bauteilbeschribung	8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, TIMERS, SPI, DALI

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Hersteller	STMICROELECTRONICS [STMicroelectronics]

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ST7DALI

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DALI COMMUNICATION MODULE (Cont’d)

11.4.10 Bi-phase Bit Detection

The clock used for sampling the DALI signal is pro-

grammed by the DCMCLK register. Each bit

phase is sampled 16 times. The bit phase level is

determined by two of three sample clock pulses

(pulses 6,7,8). The two phase levels of the bi-

phase bit are shifted into the 4-bit pre-shift register

at the 9th sample clock pulse.

Only the second phase level of the bi-phase bit is

shifted into the 16-bit shifter.

The 4-bit pre-shifter is used to detect any errors in

the received frame.

When a change of phase is detected (edge trig-

ger), the 4-bit sample clock counter (integer range

0 to15) is cleared.

Figure 43. DALI Signal Sampling

DALI Signal

12 3456 78910 11 12 13 14 15 1234 56789 10 11 12 13 14 15

Phase Detector

Shifter Clock

Edge Trigger

4-bit Pre-shifter

001

4-bit sample clock counter

16-bit Shifter

xxxx

xxx1

ST7DALI Datenblatt(PDF) 74 Page - STMicroelectronics