71M6531D Datasheet, PDF (61/115 Pages) Teridian Semiconductor Corporation – Energy Meter IC

FDS 6531/6532 005
Pulses
Samples
CE
Pre-
Processor
Data Sheet 71M6531D/F-71M6532D/F
IRQ
Data
MPU
Post -
Processor
Processed
Metering
Data
I/O RAM (Configuration RAM)
Figure 26: MPU/CE Data Flow
2.7 CE/MPU Communication
Figure 27 shows the functional relationships between the CE and the MPU. The CE is controlled by the
MPU via shared registers in the I/O RAM and in RAM.
The CE outputs two interrupt signals to the MPU: CE_BUSY and XFER_BUSY, which are connected to
the MPU interrupt service inputs as external interrupts. CE_BUSY indicates that the CE is actively
processing data. This signal will occur once every multiplexer cycle. XFER_BUSY indicates that the CE
is updating data to the output region of the RAM. This will occur whenever the CE has finished generat-
ing a sum by completing an accumulation interval determined by SUM_CYCLES * PRE_SAMPS samples.
Interrupts to the MPU occur on the falling edges of the XFER_BUSY and CE_BUSY signals.
Refer to Section 4.3 CE Interface Description for additional information on setting up the device using the
MPU firmware.
VAR
(DIO7)
PULSES
W (DIO6)
ADC
SAMPLES
APULSEW
APULSER
EXT PULSE
SAG CONTROL
DATA
MPU
DISPLAY (Memory
mapped LCD
segments)
SERIAL
(UART0/1)
EEPROM
(I²C)
CE
CE BUSY
Mux Control
XFER BUSY
DIO
INTERRUPTS
I/O RAM (Configuration RAM)
Figure 27: MPU/CE Communication
v1.2
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