FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
SERIAL INPUT PORT BIT DEFINITIONS
Tables 6 through 9 define the bit definitions as they apply to the 13 bits of input that are brought into the 34920 through the
serial input port. These signals are listed in bit order from LSB (first bit to be shifted in) to MSB (last bit to be shifted in).
Table 6. Serial Input Port Definition for Step/Step Mode
Reset
Name
Bit
Description
Value
1
1
V2_Enable
Enable bit to turn on and off the V2 regulator and the motor drivers and place the
34920 in the minimum power consumption state.
2
3
4
1
1
0
SDR2_CURR_I1_PHASEB
SDR2_CURR_I0_PHASEB
SDR2_DIR_PH_B
Second of two inputs that control the current level in the SDR2 step motor Phase B
winding.
One of two inputs that control the current level in the SDR2 step motor Phase B
winding.
Controls the direction of the current flow through Phase B of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B-
(sink).
5
6
7
1
1
0
SDR2_CURR_I1_PHASEA
SDR2_CURR_I0_PHASEA
SDR2_DIR_PH_A
Second of two inputs that control the current level in the SDR2 step motor Phase A
winding.
One of two inputs that control the current level in the SDR2 step motor Phase A
winding.
Controls the direction of the current flow through Phase A of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A-
(sink).
8
9
1
1
0
SDR1_CURR_I1_PHASEB
SDR1_CURR_I0_PHASEB
SDR1_DIR_PH_B
Second of two inputs that control the current level in the SDR1 step motor Phase B
winding.
One of two inputs that control the current level in the SDR1 step motor Phase B
winding.
10
Controls the direction of the current flow through Phase B of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B-
(sink).
11
12
13
1
1
0
SDR1_CURR_I1_PHASEA
SDR1_CURR_I0_PHASEA
SDR1_DIR_PH_A
Second of two inputs that control the current level in the SDR1 step motor Phase A
winding.
One of two inputs that control the current level in the SDR1 step motor Phase A
winding.
Controls the direction of the current flow through Phase A of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A-
(sink).
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
14