IC-MR Datasheet, PDF (26/44 Pages) IC-Haus GmbH – 13-BIT S&H SIN/COS INTERPOLATOR WITH CONTROLLER INTERFACES

iC-MR 13-BIT S&H SIN/COS
preliminary
INTERPOLATOR WITH CONTROLLER INTERFACES
INTERPOLATOR AND CYCLE COUNTER
Rev A1, Page 26/44
The configurable 37-bit cycle counter comparates the
sine and cosine signals and counts the signal cycles
independent of requests for position data. The inter-
polator resolves one signal cycle of the calibrated sine
and cosine signals to 13 bits for each position data re-
quest and synchronizes this with the cycle counter in
order to ensure a consistent position data word at all
times.
Using register CODERES it is possible to adapt the
bit length of the cycle counter to the output format. If,
for example, a total data length of 48 bits is required
at 13-bit interpolation, the value ’10’ is accrued as the
configuration for CODERES.
CODERES
Addr. 0x1B; bit 1...0
R/W
Code
Counter depth
00
37 bit (24 bit MT, 13 bit ST)
01
36 bit (24 bit MT, 12 bit ST)
10
35 bit (24 bit MT, 11 bit ST)
11
34 bit (24 bit MT, 10 bit ST)
Table 37: Cycle counter resolution
36
3 12
0
Period Counter (36:3)
Interpolation (12:0) 0 0 0
CODERES
Period Counter (36:0)
36
Interpolation (12:0)
0 12
0
Figure 13: Adjusting the counter depth
iC-MR’s output code direction can be inverted by bit ^STOFF
Addr. 0x1E; bit 7...0
R/W
DIR.
Addr. 0x1D; bit 7...0
Addr. 0x1C; bit 7...0
Addr. 0x1B; bit 7...6
Code
Function
0x00
DIR
Addr. 0x1B; bit 2
R/W
Offset value
Code
0
Code direction
Code direction not inverted
0x3FFFFFF
1
Code direction inverted
Table 39: Singleturn offset
Table 38: Inversion of code direction
MTOFF
Addr. 0x21; bit 7...0
R/W
Addr. 0x20; bit 7...0
Addr. 0x1F; bit 7...0
Code
Function
0x00
An offset for singleturn (STOFF) and multiturn
(MTOFF) data can be defined to adapt the absolute
position data. These offsets are subtracted from the
existing data.
Offset value
0xFFFFFF
Table 40: Multiturn offset