S912XHY128F0VLM Datasheet, PDF (703/802 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

Stepper Stall Detector (SSDV1) Block Description
21.3.2.1 Return-to-Zero Control Register (RTZCTL)
Module Base + 0x0000
7
6
5
4
3
2
R
0
ITG
DCOIL
RCIR
POL
SMS
W
Reset
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 21-2. Return-to-Zero Control Register (RTZCTL)
1
0
STEP
0
0
Read: anytime
Write: anytime
Table 21-3. RTZCTL Field Descriptions
Field
7
ITG
6
DCOIL
5
RCIR
4
POL
Description
Integration — During return to zero (RTZE = 1), one of the coils must be recirculated or non-driven determined
by the STEP field. If the ITG bit is set, the coil is non-driven, and if the ITG bit is clear, the coil is being recirculated.
Table 21-4 shows the condition state of each transistor from Figure 21-1 based on the STEP, ITG, DCOIL and
RCIR bits.
Regardless of the RTZE bit value, if the ITG bit is set, one end of the non-driven coil connects to the (non-zero)
reference input and the other end connects to the integrator input of the sigma-delta converter. Regardless of
the RTZE bit value, if the ITG bit is clear, the non-driven coil is in a blanking state, the converter is in a reset state,
and the accumulator is initialized to zero. Table 21-5 shows the condition state of each switch from Figure 21-1
based on the ITG, STEP and POL bits.
0 Blanking
1 Integration
Drive Coil — During return to zero (RTZE=1), one of the coils must be driven determined by the STEP field. If
the DCOIL bit is set, this coil is driven. If the DCOIL bit is clear, this coil is disconnected or drivers turned off.
Table 21-4 shows the condition state of each transistor from Figure 21-1 based on the STEP, ITG, DCOIL and
RCIR bits.
0 Disconnect Coil
1 Drive Coil
Recirculation in Blanking Mode — During return to zero (RTZE = 1), one of the coils is recirculated prior to
integration during the blanking period. This bit determines if the coil is recirculated via VDDM or via VSSM.
Table 21-4 shows the condition state of each transistor from Figure 21-1 based on the STEP, ITG, DCOIL and
RCIR bits.
0 Recirculation on the high side transistors
1 Recirculation on the low side transistors
Polarity — This bit determines which end of the non-driven coil is routed to the sigma-delta converter during
conversion or integration mode. Table 21-5 shows the condition state of each switch from Figure 21-1 based on
the ITG, STEP and POL bits.
MC9S12XHY-Family Reference Manual, Rev. 1.01
Freescale Semiconductor
703