Data Sheet 71M6531D/F-71M6532D/F
FDS 6531/6532 005
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 52.
CE Address
Name
Data
Description
0x5020
0x20
CECONFIG
See description of the CECONFIG bits in Table 52.
IA_SHUNT and/or IB_SHUNT can configure their respective current inputs to accept shunt resistor sen-
sors. 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 = 0) or WSUM_X (EQU = 2).
If EXT_PULSE = 1 and EQU = 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 = 1 and EQU = 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 54)
based on PPMC, PPMC2 and TEMP_X, the difference between die temperature and the refer-
ence/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.
Table 52: CECONFIG Bit Definitions
CECONFIG
Name
Default
Description
Sets the sag control of phase B.
[bit]
[19]
[18]
[17]
SAG_MASK1
SAG_MASK0
SAG_INT
0
0
0
Sets the sag control of phase A.
When set, enables the sag interrupt to be output on the
YPULSE pin.
[16]
EXT_TEMP
SAG_CNT
0
When set, enables the control of GAIN_ADJ by the MPU.
When 0, enables the control of GAIN_ADJ by the CE.
[15:8]
80
The number of consecutive voltage samples below SAG_THR
(0x50) before a sag alarm is declared. The maximum value is 255.
SAG_THR is at address 0x24.
[7]
[6]
FREQSEL1
FREQSEL0
0
0
Selects the phase to be used for the frequency monitor.
FREQSEL1/FREQSEL0 = 0/0: Phase A
FREQSEL1/FREQSEL0 = 0/1: Phase B
88
© 2005-2009 TERIDIAN Semiconductor Corporation
v1.2