DA6512.003
2 December, 2016
REGISTER AND EEPROM DATA ADDRESSES
MAS6512 includes a 32 bytes (256 bits) EEPROM
data memory and thirteen registers. Five bytes (40
bits) of EEPROM are reserved for trim values and
programmable I2C device address but the
remaining 27 bytes (216 bits) are free for storing
sensor calibration and other data. See table 1 on
the previous page for register and EEPROM data
addresses.
The Measurement control register (E2/62HEX) is
used for configuring and starting an A/D conversion.
The CS (E3/63HEX) and the CR (E4/64HEX) capacitor
matrix registers select internal capacitors which are
connected from the CS and the CR pins
respectively to the CC pin. Both capacitor values
can be chosen independently between 0pF and
22pF in 86fF steps.
In the SPI serial bus the address bit A7 selects
between write (A7=0) and read (A7=1) operation. In
the I2C serial bus A7 is always high (A7=1) and
selection between write and read operation is done
with the LSB bit of the I2C device address. See
table 11 in chapter SERIAL DATA INTERFACE
CONTROL. The MAS6512 has both hard wired and
programmable I2C device addresses. The
The Gain register (E5/65HEX) controls the gain of the
CDC front-end. Together with the CS and CR
values the gain determines the input capacitance
conversion range.
The Oscillator frequency control register (E6/66HEX
)
is used only during internal clock oscillator trimming.
During trimming there is searched register value
which gives closest to the nominal 200 kHz
oscillator frequency. However the internal clock
oscillator frequency is trimmed by MAS during wafer
level testing and the trimming value is stored into
the Oscillator frequency trim data EEPROM
address (C6/46HEX). Thus there is no need to adjust
the factory stored clock oscillator trimming value. In
normal operation the trim value is automatically
read from the EEPROM memory in the beginning of
each conversion.
programmable
device
address
is
factory
programmed to value EC HEX (%11101100) which is
the same as the hard wired device address of
MAS6512. When unique device address is needed
it can be programmed to the Programmable I2C
Device Address register (C2HEX). The MAS6512 will
respond to both hard wired and programmed I2C
device addresses.
MAS6512 has four trim registers: CS capacitor
matrix register (E3/63HEX), CR capacitor matrix
register (E4/64HEX), Gain register (E5/65HEX) and
Oscillator frequency register (E6/66HEX). These are
marked with “R+T” in table 1. Each of these
registers has a corresponding EEPROM byte where
trim values can be permanently stored. These are
marked with “E+T” in table 1. Trim values are
automatically read from EEPROM in the beginning
of each conversion when this feature is enabled in
the trimming control register (ED/6DHEX). When
disabled it is possible to test different trim data in
the trim registers before final trimming values are
found and stored in the EEPROM.
EEPROM write enable register (E9/69HEX) is used
for enabling EEPROM write since by default the
EEPROM is write protected.
The 16-bit A/D conversion result (capacitance,
temperature or monitored supply voltage) is stored
into two registers EAHEX (MSB, most significant
byte) and EBHEX (LSB, least significant byte).
The EEPROM status register (EC/6CHEX) reflects
the EEPROM error correction status. This register
can be used to verify that the EEPROM operation
has finished without errors.
The Trimming control register (ED/6DHEX) defines
whether the trim data in the EEPROM or in the
registers are used during operation. The default
setting is that all trim data is automatically read from
the EEPROM memory in the beginning of each
conversion. See the Trimming control register
description for details.
Reset register (E0/60HEX) does not contain any data.
Any dummy data written to this register forces a
reset.
A reset initializes all control registers
(addresses E1HEX…EEHEX) to a zero value.
Test register (E1/61HEX) is mainly used for testing
and trimming purposes. See table 2 in chapter
TEST REGISTER. If an external clock signal is
used the test register is needed for selecting the
external clock signal.
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