Data Sheet 71M6531D/F-71M6532D/F
Table 57: CESTATUS (CE RAM 0x80) Bit Definitions
FDS 6531/6532 005
CESTATUS [bit]
Name
Description
31:29
Not Used
These unused bits will always be zero.
F0 is a square wave at the exact fundamental frequency for the
phase selected with the FREQSELn bits in CECONFIG.
28
27
F0
Reserved
Normally zero. Becomes one when VB remains below SAG_THR for
SAG_CNT samples. Will not return to zero until VB rises above
SAG_THR.
26
SAG_B
Normally zero. Becomes one when VA remains below SAG_THR for
SAG_CNT samples. Will not return to zero until VA rises above
SAG_THR.
25
SAG_A
24:0
Not Used
These unused bits will always be zero.
The CE is initialized and its functions are controlled by the MPU using CECONFIG. This register contains
in packed form SAG_CNT, FREQSEL, EXT_PULSE, I0_SHUNT, I1_SHUNT, PULSE_SLOW and PULSE_FAST.
The CECONFIG bit definitions are given in Table 58.
CE Address
Name
Data
Description
0x20
CECONFIG
0x5020
See description of the CECONFIG bits in Table 58.
IA_SHUNT and/or IB_SHUNT can configure their respective current inputs to accept shunt resistor sensors.
In this case the CE provides an additional gain of 8 to the selected current input. WRATE may need to be
adjusted based on the values of IA_SHUNT and IB_SHUNT. Whenever IA_SHUNT or IB_SHUNT are set to
1, In_8 (in the equation for Kh) is assigned a value of 8.
The CE pulse generator can be controlled by either the MPU (external) or CE (internal) variables. Control
is by the MPU if EXT_PULSE = 1. In this case, the MPU controls the pulse rate by placing values into
APULSEW, APULSER, APULSE2 and APULSE3. By setting EXT_PULSE = 0, the CE controls the pulse rate
based on W0SUM_X and VAR0SUM_X (EQU[2:0] = 0) or WSUM_X (EQU[2:0] = 2).
If EXT_PULSE = 0 and EQU[2:0] = 2, the pulse inputs are W0SUM_X + W1SUM_X and VAR0SUM_X +
VAR1SUM_X. In this case, creep cannot be controlled since creep is an MPU function.
If EXT_PULSE = 0 and EQU[2:0] = 0, the pulse inputs are W0SUM_X if I0SQSUM_X > I1SQSUM_X and
W1SUM_X, if I1SQSUM_X > I0SQSUM_X.
The 71M6531 Demo Code creep function halts both internal and external pulse generation.
The EXT_TEMP bit controls the temperature compensation mode:
•
When EXT_TEMP = 0 (internal compensation), the CE will control the gain using GAIN_ADJ (see Table 60)
based on PPMC, PPMC2 and TEMP_X, the difference between die temperature and the reference /
calibration temperature TEMP_NOM. Since PPMC and PPMC2 reflect the typical behavior of the
reference voltage over temperature, the internal temperature compensation eliminates the effects of
temperature-related errors of VREF only.
•
When EXT_TEMP = 1 (external compensation), the MPU is allowed to control the CE gain using
GAIN_ADJ, based on any algorithm implemented in MPU code.
The FREQSEL1 and FREQSEL0 bits select the phase used to control the CE-internal PLL. CE accuracy
depends on the channel selected by the FREQSEL1 and FREQSEL0 bits receiving a clean voltage signal.
90
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