DATA SHEET
HAL815
5. Programming of the Sensor
– Read a register (see Fig. 5–3)
After evaluating this command, the sensor answers
with the Acknowledge Bit, 14 Data Bits, and the
Data Parity Bit on the output.
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.
– Programming the EEPROM cells (see Fig. 5–4)
After evaluating this command, the sensor answers
with the Acknowledge Bit. After the delay time tw,
the supply voltage rises up to the programming volt-
age.
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
– Activate a sensor (see Fig. 5–5)
at the beginning of each telegram. The bit time for the
output is defined through the Acknowledge Bit.
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 kΩ 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.
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
t
t
f
r
V
DDH
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).
t
t
p0
p0
logical 0
or
V
V
DDL
DDH
There are 4 kinds of telegrams:
t
p1
– Write a register (see Fig. 5–2)
t
t
p0
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.
p0
logical 1
or
t
V
p1
DDL
Fig. 5–1: Definition of logical 0 and 1 bit
Table 5–1: Telegram parameters
Symbol
Parameter
Pin
Min.
Typ.
Max.
Unit
Remarks
V
Supply Voltage for Low Level
during Programming
1
5
5.6
6
V
DDL
V
Supply Voltage for High Level
during Programming
1
6.8
8.0
8.5
V
DDH
t
t
t
t
Rise time
Fall time
1
1
1
3
0.05
0.05
1.8
4
ms
ms
ms
ms
r
f
Bit time on V
1.7
2
1.75
3
t
is defined through the Sync Bit
p0
p0
DD
Bit time on output pin
t
is defined through the
pOUT
pOUT
Acknowledge Bit
t
Voltage Change for logical 1
1, 3
1
50
65
80
%
V
% of t or t
p1
p0
pOUT
V
Supply Voltage for
12.4
12.5
12.6
DDPROG
Programming the EEPROM
t
t
Programming Time for EEPROM
Rise time of programming voltage
1
1
95
100
0.5
105
1
ms
ms
PROG
0.2
rp
Micronas
Feb. 7, 2006; 6251-537-3DS
25
MICRONAS [ MICRONAS ]
