MPR081

Sensors

Freescale Semiconductor

11

Table 10. FIFO Register Format

Register

R/W

Register

Address

Register Data

D7

D6

D5

D4

D3

D2

D1

D0

1. Reading or writing the MPR08 clears IRQ, IRQ will only be re-asserted by an event after the FIFO has been emptied by read(s).

1

0x00

More

Flag

Empty

Flag

Overflow

Flag

Rotary Pad that has been detected as pressed

FIFO Status

Clear the FIFO.

Subsequent reads without any intervening

addition(s) to the FIFO will return

1'b0100000

0

0x00

Clear FIFO (D7 - D0 data is don’t care; it is not stored)

This data is not the last FIFO item.

FIFO has not overflowed.

1

1

0

0

X

X

X

X

X

This data is not the last FIFO item.

FIFO did overflow, discarding the most

recent entries.

1

0

1

X

X

X

X

X

This data is the last FIFO item.

FIFO has not overflowed.

Subsequent reads without any intervening

addition(s) to the FIFO will return

1'b0100000

0

0

0

X

X

X

X

X

This data is the last FIFO item.

FIFO did overflow, discarding the most

recent entries

(FIFO overflow flag will now be cleared).

Subsequent reads without any intervening

addition(s) to the FIFO will return

1'b0100000

0

0

1

X

X

X

X

X

FIFO is empty

0

1

0

0

0

0

0

0

Rotary Input Events

Rotary has been released

1

0x00

X

X

X

0

0

0

0

0

Rotary is in position North (N)

X

X

X

1

0

0

0

0

Rotary is in position NNE

X

X

X

1

0

0

0

1

Rotary is in position NE

X

X

X

1

0

0

1

0

Rotary is in position NEE

X

X

X

1

0

0

1

1

Rotary is in position East (E)

X

X

X

1

0

1

0

0

Rotary is in position SEE

X

X

X

1

0

1

0

1

Rotary is in position SE

X

X

X

1

0

1

1

0

Rotary is in position SSE

X

X

X

1

0

1

1

1

Rotary is in position South (S)

X

X

X

1

1

0

0

0

Rotary is in position SSW

X

X

X

1

1

0

0

1

Rotary is in position SW

X

X

X

1

1

0

1

0

Rotary is in position SWW

X

X

X

1

1

0

1

1

Rotary is in position West (W)

X

X

X

1

1

1

0

0

Rotary is in position NWW

X

X

X

1

1

1

0

1

Rotary is in position NW

X

X

X

1

1

1

1

0

Rotary is in position NNW

X

X

X

1

1

1

1

1