IC-MHM Datasheet, PDF (25/63 Pages) IC-Haus GmbH – 14-BIT ABSOLUTE ANGLE HALL ENCODER

iC-MHM
14-BIT ABSOLUTE ANGLE HALL ENCODER
Rev D1, Page 25/63
Continuing the example, with an input rotation speed of
72 000 RPM, the magnet moves by an angle of
72 000 _{· 145 µs · 360◦ = 62.64◦}
60
during the multiturn SSI transmission. To guarantee
not exceeding the angle tolerance for one synchroniza-
tion bit (90 °), the alignment error between the multiturn
sensor and the iC-MHM can thus be no more than 27 °.
The multiturn interface is disabled when SBL_MTI = 0,
but the iC-MHM’s internal multiturn counter still counts
turns. When the multiturn interface is disabled, the MCL
output and MDI input can be used as additional discrete
I/O. Refer to DIGITAL I/O PORT on page 26 for more
information.
Multiturn Error Bits (EBL_MTI)
Up to four error bits from the external multiturn sensor
can be included in the SSI transmission.
EBL_MTI
Value
0
1
2
3
4
5 ...7
Address 0x02; bits 6:4
Error Bits
0 (Error bits not used)
1
2
3
4
Reserved (Do not use)
Error bits are active low. If any bit is 0, ERR_MTI in
the error status register is set. This activates the error
output (pin NERR low) and activates the error bit in the
BiSS SCD, SPI position read command response, and
extended SSI frame (nERR = nE = 0). Refer to STATUS
REGISTERS on page 30 for more information.
Multiturn Interface Feedthrough Mode
Multiturn interface feedthrough mode allows the exter-
nal multiturn sensor to be read directly via the serial
interface in SSI mode for diagnostic purposes. If the
serial interface is set to SSI mode (ENSSI = 1), multi-
turn interface feedthrough mode is enabled when
GET_MTI = 1.
GET_MTI
Value
0
1
Address 0x02; bit 7
Multiturn Interface Feedthrough Mode
Disabled
Enabled
Table 26: Multiturn Interface Feedthrough Mode
Table 25: Multiturn Error Bits
Figure 16: SSI Multiturn Interface Feedthrough
In multiturn interface feedthrough mode, the serial clock
input (MA) signal is sent directly to the multiturn inter-
face clock output (MCL), and the data clocked in on
the multiturn data input (MDI) is supplementing the in-
ternal position data in the SSI transmission. Refer to
SERIAL INTERFACE: SSI MODE on page 43 for more
information.