Infineon Technologies TLE5012B - Signed Registers and Twos Complement

TLE5012B
SSC Registers
User’s Manual 70 Rev. 1.2, 2018-02
6.1.3 Signed registers and Two’s complement
Many registers are described as signed registers. Data in the registers such as the Angle Speed and also
configuration parameters such as the X and Y Offset, the Amplitude Synchronicity, Orthogonality Correction and
the Offset Temperature Coefficients are, among others, signed registers. That means, that they are stored in two’s
complement. The Angle Value is also a signed register (-180°...179.9°), but can also be viewed as unsigned
(0...359.9°).
A two’s complement number is generated by the following equation:
(6.1)
For example, if the AVAL Register value is 1100 1101 1001 0011 the MSB indicates that the RD_AV field is “high”
and a new angle value is present (ANG_VAL). ANG_VAL are represented by the following 15 bits (100 1101 1001
0011). Therefore the angle value is:
(6.2)
And if we calculate the angle (formula provided in the AVAL register description) we can calculate the angle:
(6.3)
∑
−
=
−
∗+∗−=
2
0
1
22
N
i
i
i
N
MSB
bbValue
12909121612825610242048163842*12*12*12*12*12*1
2*12*12*12*12*02*02*12*02*02*1
2*12*02*12*12*02*02*122
0147810
1114151514151315121511151015915815
715615515415315215115
2
0
1
−
=+++
+
+
+
+
−
=
++++++
++−=++++++++
+++++++−=∗+∗−=
−−−−−−−−
−−−−−−−
−
=
−
∑
N
i
i
i
N
MSB
bbVa lue
°−=−
°
=
°
=° 82.141)12909(*
32768
360
][_
2
360
][
15
digitsVALANGAngle