71M6511 Maxim, 71M6511 Datasheet - Page 13

• Manufacturer Part Number: 71M6511
• Description: The 71M6511 and 71M6511H are highly integrated SoCs with an MPU core, RTC, flash, and LCD driver
• Manufacturer: Maxim

Real-Time Monitor
The CE contains a Real Time Monitor (RTM), which can be programmed to monitor four selectable CE RAM locations at full
sample rate. The four monitored locations are serially output to the TMUXOUT pin via the digital output multiplexer at the
beginning of each CE code pass (see the Test Ports Section for details)
CE Functional Overview
The ADC processes one sample per channel per multiplexer cycle. Figure 4 shows the timing of the samples taken during one
multiplexer cycle.
The number of samples processed during one accumulation cycle is controlled by the I/O RAM registers PRE_SAMPS
(0x2001[7:6]) and SUM_CYCLES (0x2001[5:0]). The integration time for each energy output is
For example, PRE_SAMPS = 42 and SUM_CYCLES = 50 will establish 2100 samples per accumulation cycle. PRE_SAMPS = 100
and SUM_CYCLES = 21 will result in the exact same accumulation cycle of 2100 samples or 833ms. After an accumulation
cycle is completed, the XFER_BUSY interrupt signals to the MPU that accumulated data are available.
The end of each multiplexer cycle is signaled to the MPU by the CE_BUSY interrupt. At the end of each multiplexer cycle,
status information, such as sag data and the digitized input signal, is available to the MPU.
Figure 5 shows the accumulation interval resulting from MUX_DIV = 1, PRE_SAMPS = 42 and SUM_CYCLES = 50, consisting of
2100 samples of 397µs each, followed by the XFER_BUSY interrupt. The sampling in this example is applied to a 50Hz signal.
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PRE_SAMPS * SUM_CYCLES / 2520.6, where 2520.6 is the sample rate [Hz] (for MUX_DIV = 1)
20ms
20ms
IA
IA
© 2005–2010 Teridian Semiconductor Corporation
VA
VA
Figure 4: Samples in Multiplexer Cycle
Figure 5: Accumulation Interval
IB
IB
833ms
833ms
Single-Phase Energy Meter IC
13/32768Hz = 397µs
13/32768Hz = 397µs
per mux cycle
per mux cycle
71M6511/71M6511H
1/32768Hz =
1/32768Hz =
30.518µs
30.518µs
DATA SHEET
Interrupt to MPU
Interrupt to MPU
XFER_BUSY
XFER_BUSY
NOVEMBER 2010
V2.7