Sensors

22

Freescale Semiconductor

MMA690xQ

3.2.2

Acceleration Data Transfer

The format of an acceleration data transfer is illustrated in Figure 3-2. Response to acceleration data transfers is summarized

in Table 3-8. Note that a number of reserved values are defined to indicate error exceptions. MMA690xQ will produce signed or

unsigned data depending upon the state of the SD bit in the DSPCFG register, as described in Section 2.1.4.

T[1:0] Transfer type code

S[2:0]: Status code

Figure 3-2 Communications Protocol, Acceleration Data Transfer

Table 3-8. Range of Output, Communications Protocol

11-bit Data Value

Definition

Unsigned

Decimal

Hex

2047

7FF

Critical/Reset Exception Value

2046

7FE

Invalid Axis Selection

2045

7FD

Internal Signal Path Overflow

2044

7FC

Overrange Value

2043

7FB

Maximum Positive Signal Level

•

•

•

•

•

•

1024

400

Zero Signal Level

•

•

•

•

•

•

5

005

Minimum Negative Signal Level

4

004

Underrange Value

3

003

Internal Signal Path Underflow

2

002

SPI Clock Fault

1

001

0

000

Reserved Value

SCLK

BIT

15

MOSI

MISO

CS

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

D5

D4

D3

D2

D1

D0

0

T1

T0

S2

S1

D6

D7

D8

D9

D10

S0

P

000000000000

00