IC-TW14 Datasheet, PDF (15/33 Pages) IC-Haus GmbH – IC-PMX Companion Chip

iC-TW14
iC-PMX Companion Chip
Rev A1, Page 15/33
STATUS.NOSSI = 1 indicates that the iC-TW14 is not
ready to provide multiturn position data over the SSI
multiturn interface. During normal operation, this bit is
the logical inverse of the state of iC-TW14 pin MRDY.
STATUS.STOP = 1 indicates that the iC-TW14 has
stopped working because STATUS.CF = 1, STA-
TUS.EFLAG =/ 0, STATUS.FCF = 1, or mode 1 or 2 (di-
agnostic mode 2), mode 30 (MRDY low), 31 (MRDY
high), or 40 (SSI test mode) is active. To clear this con-
dition re-synchronize the iC-TW14 using the RESYNC
command (8).
STATUS.MTM = 1 indicates that the multiturn position
as tracked by the iC-TW14 does not match the multiturn
position stored in the FRAM.
STATUS.HSC = 1 indicates that the iC-PMX singleturn
Hall signals are being clipped. This condition occurs
if PMXGAIN is too large or the magnetic field is too
strong.
STATUS.MLF = 1 indicates that the singleturn Hall sen-
sor signal amplitude is too low, probably because the
magnet is too far away from the iC-PMX. Specifically,
STATUS.MLF = 1 if AMP < AMP_MAG_LOSS. See
AMP_MAG_LOSS on page 18 for more information
STATUS.HGW = 1 indicates that the iC-PMX Hall gain
value is wrong but cannot be changed. This only occurs
when the auto-gain feature is disabled and the iC-PMX
Hall gain value is wrong. The current iC-PMX Hall gain
value is available in the GAIN register (0x49).
STATUS.FAD = 1 indicates that a direct FRAM access
command (21 – 25) failed, possibly because an illegal
address was specified or the iC-PMX RDY pin indicated
low VDD. See DIRECT FRAM ACCESS on page 28 for
more information.
A STATUS.FAD = 1 condition can be cleared using a
RESET (7) or RESYNC (8) command. See MODE/-
CMD on page 19 for more information.
STATUS.EFLAG are the FRAM error flag bits read from
iC-PMX 0x005[7:6].
Value
0
1
2
3
STATUS.EFLAG (0x03 Bits 3:2)
Description
No fault
Counter over/underflow fault
Uncorrectable Error Correction Code fault
Incomplete write fault
Table 13: Multiturn Position Read Errors
If STATUS.EFLAG = 0, the multiturn position value read
from the FRAM is valid. If STATUS.EFLAG =/ 0, the
multiturn position value read from the FRAM is invalid,
the counter in the FRAM is disabled, and the iC-TW14
is stopped (STATUS.STOP = 1). A STATUS.EFLAG =/ 0
condition can only be cleared by over-writing the FRAM
contents. See DIRECT FRAM ACCESS on page 28 for
more information.
STATUS.PNR = 1 indicates that the iC-PMX is not ready
(iC-PMX pin RDY low). This may be because VCC is
less than VDDOK (iC-PMX spec. item 705).
STATUS.SYNC = 1 indicates that the iC-TW14 is in the
process of synchronizing itself with the iC-PMX. This
is true right after power-up or a RESYNC (8) com-
mand. When the synchronization is complete, STA-
TUS.SYNC = 0. This is the condition during normal
operation of the iC-TW14.
PRAMP
PRAMP is a read/write register that sets the iC-PMX
ramp parameters used to activate a positive current
ramp.
PRAMP (0x10)
Bits
Description
15:8
Reserved (must be zero)
7:0
iC-PMX RAMP(7:0)
Table 14: PRAMP Register
STATUS.FCF = 1 indicates that there is a problem with
the iC-TW14 configuration data stored in the FRAM and
that the iC-TW14 is disabled (STATUS.STOP = 1). In
this case, new configuration data must be written to the
FRAM using the WRITE command (4). See MODE/-
CMD on page 19 for more information.
The LSB of the PRAMP register is written to iC-PMX
address 0x01 when a positive current ramp is re-
quired. See Wiegand Module Excitation in the iC-PMX
datasheet for more information.