HAL880 datasheet(26/34 Pages) MICRONAS

26 / 34 page

HAL880

DATA SHEET

Feb. 23, 2009; DSH000152_001EN

Micronas

5. Programming of the Sensor

5.1. Definition of Programming Pulses

The sensor is addressed by modulating a serial tele-

gram on the supply voltage. The sensor answers with

a serial telegram on the output pin.

The bits in the serial telegram have a different bit time

for the VDD-line and the output. The bit time for the

VDD-line is defined through the length of the Sync Bit

at the beginning of each telegram. The bit time for the

output is defined through the Acknowledge Bit.

A logical “0” is coded as no voltage change within the

bit time. A logical “1” is coded as a voltage change

between 50% and 80% of the bit time. After each bit, a

voltage change occurs.

5.2. Definition of the Telegram

Each telegram starts with the Sync Bit (logical 0),

3 bits for the Command (COM), the Command Parity

Bit (CP), 4 bits for the Address (ADR), and the

Address Parity Bit (AP).

There are 4 kinds of telegrams:

– Write a register (see Fig. 5–2 on page 28)

After the AP Bit follow 14 Data Bits (DAT) and the

Data Parity Bit (DP). If the telegram is valid and the

command has been processed, the sensor answers

with an Acknowledge Bit (logical 0) on the output.

– Read a register (see Fig. 5–3 on page 28)

After evaluating this command, the sensor answers

with the Acknowledge Bit, 14 Data Bits, and the

Data Parity Bit on the output.

– Programming the EEPROM cells (see Fig. 5–4 on

page 28)

After evaluating this command, the sensor answers

with the Acknowledge Bit. After the delay time tw,

the supply voltage rises up to the programming

voltage.

– Activate a sensor (see Fig. 5–5 on page 28)

If more than one sensor is connected to the supply

line, selection can be done by first deactivating all

sensors. The output of all sensors will be pulled to

ground by the internal 10 k

Ω resistors. With an Acti-

vate pulse on the appropriate output pin, an individ-

ual sensor can be selected. All following commands

will only be accepted from the activated sensor.

Fig. 5–1: Definition of logical 0 and 1 bit

tp0

logical 0

VDDH

VDDL

tp0

logical 1

VDDH

VDDL

tp0

tp1

HAL880 Datasheet(PDF) 26 Page - Micronas

HAL880 Datasheet(HTML) 26 Page - Micronas

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

Datasheet Download

Link URL