Maxim Integrated 71M6534 Energy Meter IC Family Software - Manual (Page 76)

71M653X Software User’s Guide
Bit
No.
Discussion Name
SOFTWARE 23 A software defect was detected. error_software() was called. E.g.: In banked code, a
subroutine address outside common code is given as a callback routine. Or: irq_enable()
(interrupt disable) is called more than irq_disable().
SAGA 25 Element A has a sag. Set in real time by the CE and detected by the ce_busy interrupt
(ce_busy_isr() in ce.c) within 8 sample intervals, about 2.6ms. A transition from normal
operation to SAGA causes the power registers to be saved, because the demo PCB is
powered from element A. For a multiphase power supply, modify the bit mask constant
POWERED_PHASE, in options.h to select the sag bits from the most-significant 8 bits of
Status, then recompile. In this case, all the bits in POWERED_PHASE must become
asserted to cause a save of the powered registers.
SAGB 26 Element A has a sag. Set in real time by the CE and detected by the ce_busy interrupt
(ce_busy_isr() in ce.c) within 8 sample intervals, about 2.6ms. On the 6520, the demo
code operates with an equation that does not use element B’s voltage, but the meter
simulates this by wiring element A’s V to VB on the chip.
SAGC‡ 27 Element C has a sag. Works like other sag bits.
F0_CE 28 A square wave at the line frequency, with a jitter of up to 8 sample intervals, about 2.6ms.
The jitter is caused because the ce_busy interrupt only executes all of its code every 8
th
sample interval.
ONE_SEC 31 Changes each accumulation interval.
‡ Three phase chips (i.e. 6533, 6534) only.
Table 5-13: MPU Status Bits
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