MPR083

Sensors

8

Freescale Semiconductor

Preliminary

When performing read-after-write verification, remember to re-set the command byte’s address because the stored command

byte address will generally have been auto-incremented after the write (Section 2.4).

Figure 12. ‘n’ Data Bytes Received

2.3.8

Operation with Multiple Master

once a master issues a start/repeated start condition, that master owns the bus until a stop condition occurs. If a master that does

not own the bus attempts to take control of that bus, then improper addressing may occur. An address may always be rewritten

2.3.9

Device Reset

The RST is an active-low software reset. This is implemented in the Configuration Register by activating the RST bit. When

asserted, the device clears any transaction to or from the MPR083 on the serial interface and configures the internal registers to

the same state as a power-up reset (Table 4). The MPR083 then waits for a START condition on the serial interface.

The sensor controller is capable of operating down to 1.8 V, however, in order for the sensor controller to exit reset and startup

is required in applications that require regulated operation in the 1.8 V to 2.0 V range. In the case that the application uses an

unregulated battery, then the battery must initially provide at least 2.0 V to correctly power-up the sensor controller which limits

battery selection to the 2.0 V to 3.6 V range.

Figure 13. Low Voltage (1.8 V - 2.0 V) Power-up Sequence

SAAA P

1

SLAVE ADDRESS

COMMAND BYTE

DATA BYTE

acknowledge from MPR083

R/W

nbytes

auto-increment memory

word address

D15 D14 D13 D12 D11 D10 D9 D8

D1 D0

D3 D2

D5 D4

D7 D6

Howcommand byte and data byte

map into MPR083's registers

acknowledge from

MPR083

acknowledge from

MPR083

Established Comms with

Sensor Controller?

i.e. Read from FIFO

Is Data valid? (0 x 40)

Idle Delay Loop

To Sensor Controller

1.8 V to 2.0 V

False

True