Xtrinsic MMA51xxKW PSI5 Inertial Sensor

Document Number: MMA51xxKW
Rev. 11, 08/2012
Freescale Semiconductor
Data Sheet: Technical Data
Xtrinsic MMA51xxKW
PSI5 Inertial Sensor
MMA51xxKW
The MMA51xxKW family, a SafeAssure solution, includes the AKLV27 and PSI5
Version 1.3 compatible overdamped Z-axis satellite accelerometers.
Features
Bottom View
•
•
•
•
±60g to ±480g Full-Scale Range
Selectable 400 Hz, 3-Pole, or 4-pole Low-Pass Filter
Single Pole High Pass Filter with Fast Startup and Output Rate Limiting
PSI5 Version 1.3 Compatible
– PSI5-P10P-500/3L Compatible
– Programmable Time Slots with 0.5 μs Resolution
– Selectable Baud Rate: 125 kBaud or 190.5 kBaud
– Selectable Data Length: 8 or 10 bits
– Selectable Error Detection: Even Parity, or 3-bit CRC
– Optional Daisy Chain with External Low-Side Switch
– Two-Wire Programming Mode
• 16 μs Internal Sample Rate, with Interpolation to 1 μs
• Pb-Free 16-Pin QFN, 6 by 6 Package
• Qualified AECQ100, Revision G, Grade 1 (-40°C to +125°C)
(http://www.aecouncil.com/)
16-PIN QFN
CASE 2086-01
VBUF
TEST
BUS_SW
VSSA
Top View
16 15 14 13
Typical Applications
VCC 1
• Airbag Front and Side Crash Detection
12 VSSA
17
VSS 2
11 VREGA
IDATA 3
Range
Package
Shipping
MMA5106KW
Z
±60g
2086-01
Tubes
MMA5112KW
Z
±120g
2086-01
Tubes
MMA5124KW
Z
±240g
2086-01
Tubes
MMA5148KW
Z
±480g
2086-01
Tubes
MMA5106KWR2
Z
±60g
2086-01
Tape & Reel
MMA5112KWR2
Z
±120g
2086-01
Tape & Reel
MMA5124KWR2
Z
±240g
2086-01
Tape & Reel
MMA5148KWR2
Z
±480g
2086-01
Tape & Reel
For user register array programming, please consult your Freescale
representative.
© 2010-2012 Freescale Semiconductor, Inc. All rights reserved.
7
8
DIN
Axis
6
DOUT
Device
5
SLCK
ORDERING INFORMATION
9 VREG
PCM
VSS
10 CS
4
PIN CONNECTIONS
Application Diagram
VVBUF
VBUF
VCC
VREG
IDATA
VREGA
C4
C5
C6
VCE
R1
R2
MMA51xx
C2
C1
VSSA
CS
SCLK
VSS
VSS
DO
Note: Pin names and references
may differ from PSI5 V1.3
pin names and references
C3
R3
M1
BUS_SW
DI
Optional for
Daisy Chain
PCM
VSS_OUT
Figure 1. Application Diagram
External Component Recommendations
Ref Des
Type
Description
Purpose
C1
Ceramic
2.2 nF, 10%, 50V minimum, X7R
VCC Power Supply Decoupling and Signal Damping
C3
Ceramic
470 pF, 10%, 50V minimum, X7R
IDATA Filtering and Signal Damping
C2
Ceramic
15 nF, 10%, 50V minimum, X7R
VCC Power Supply Decoupling
C4, C5, C6
Ceramic
1 μF, 10%, 10V minimum, X7R
Voltage Regulator Output Capacitor(s)
R1
General Purpose
82Ω, 5%, 200 PPM
VCC Filtering and Signal Damping
R2
General Purpose
27Ω, 5%, 200 PPM
IDATA Filtering and Signal Damping
R3
General Purpose
20 kΩ, 5%, 200 PPM
M1
N-Channel MOSFET
—
Gate Resistor for External Low-Side Daisy Chain FET
Low-Side Daisy Chain Transistor
xxxxxxx
xxxxxxx
Z: 0g
Z: 0g
xxxxxxx
xxxxxxx
xxxxxxx
xxxxxxx
Device Orientation
Z: 0g
xxxxxxx
xxxxxxx
Z: 0g
Z: +1g
Z: -1g
EARTH GROUND
Figure 2. Device Orientation Diagram
MMA51xxKW
2
Sensors
Freescale Semiconductor, Inc.
Internal Block Diagram
VCC
Buffer
Voltage
Regulator
Reference
Voltage
VBUF
VBUF
VREF
Digital
Voltage
Regulator
VREG
Analog
Voltage
Regulator
VREGA
CS
VREG
VREGA
VBUF
VSSA
SCLK
Low Voltage
Detection
SPI
DIN
Sync Pulse
Detection
Control
Logic
DOUT
VCC
Programming
Interface
IDATA
OTP
Serial
Encoder
Array
VSS
Daisy Chain
Switch Driver
BUS_SW
VREG
Self-Test
Interface
VREGA
VREG
Control
In
Status
Out
DSP
g-cell
ΣΔ
Converter
SINC Filter
IIR
LPF
Compensation
Offset
Monitor
HPF
PCM
Encoder
PCM
Figure 3. Block Diagram
MMA51xxKW
Sensors
Freescale Semiconductor, Inc.
3
VBUF
TEST
BUS_SW
Pin Connections
VSSA
1
16 15 14 13
VCC 1
12 VSSA
17
VSS 2
11 VREGA
IDATA 3
10 CS
5
6
7
8
SLCK
DOUT
DIN
9 VREG
PCM
VSS 4
Figure 4. Top View, 16-Pin QFN Package
Table 1. Pin Description
Pin
Pin
Name
Formal Name
Definition
1
VCC
Supply
This pin is connected to the PSI5 power and data line through a resistor and supplies power to the device. An external capacitor must be connected between this pin and VSS. Reference Figure 1.
2
VSS
Digital GND
3
IDATA
Response
Current
4
VSS
Digital GND
5
PCM
PCM
Output
This pin provides a 4 MHz PCM signal proportional to the acceleration data for test purposes. The output can be enabled via
OTP. Reference Section 3.5.3.7. If unused, this pin must be left unconnected.
6
SCLK
SPI Clock
This input pin provides the serial clock to the SPI port for test purposes. An internal pulldown device is connected to this pin.
This pin must be grounded or left unconnected in the application.
7
DOUT
SPI Data Out
This pin functions as the serial data output from the SPI port for test purposes. This pin must be left unconnected in the application.
8
DIN
SPI Data In
This pin functions as the serial data input to the SPI port for test purposes. An internal pulldown device is connected to this
pin. This pin must be grounded or left unconnected in the application.
9
VREG
Digital
Supply
This pin is connected to the power supply for the internal digital circuitry. An external capacitor must be connected between
this pin and VSS. Reference Figure 1.
10
CS
Chip Select
This input pin provides the chip select to the SPI port for test purposes. An internal pullup device is connected to this pin.This
pin must be left unconnected in the application.
11
VREGA
Analog
Supply
This pin is connected to the power supply for the internal analog circuitry. An external capacitor must be connected between
this pin and VSSA. Reference Figure 1.
12
VSSA
Analog GND
13
VBUF
Power
Supply
14
TEST
Test Pin
15
BUS_SW
Bus Switch
Gate Drive
16
VSSA
Analog GND
PAD
Die Attach Pad
Corner
Pads
Corner Pads
17
This pin is the power supply return node for the digital circuitry.
This pin is connected to the PSI5 power and data line through a resistor and modulates the response current for PSI5 communication. Reference Figure 1.
This pin is the power supply return node for the digital circuitry.
This pin is the power supply return node for the analog circuitry.
This pin is connected to a buffer regulator for the internal circuitry. The buffer regulator supplies both the analog (VREGA) and
digital (VREG) supplies to provide immunity from EMC and supply dropouts on VCC. An external capacitor must be connected
between this pin and VSS. Reference Figure 1.
This pin is must be grounded or left unconnected in the application.
This pin is the drive for a low-side daisy chain switch. When daisy chain mode is enabled, this pin is connected to the gate of
an n-channel FET which connects VSS to VSS_OUT. Reference Figure 1. If unused, this pin must be left unconnected.
This pin is the power supply return node for the analog circuitry.
This pin is the die attach flag, and is internally connected to VSS. Reference Section 7 for die attach pad connection details.
The corner pads are internally connected to VSS.
MMA51xxKW
4
Sensors
Freescale Semiconductor, Inc.
2
Electrical Characteristics
2.1
Maximum Ratings
Maximum ratings are the extreme limits to which the device can be exposed without permanently damaging it.
#
Rating
1
2
3
Supply Voltage (VCC, IDATA)
Reverse Current ≤ 160 mA, t ≤ 80 ms
Continuous
Transient (< 10 μs)
4
VBUF, Test, BUS_SW
5
VREG, VREGA, SCLK, CS, DIN, DOUT, PCM
6
Powered Shock (six sides, 0.5 ms duration)
7
8
Symbol
Value
Unit
VCC_REV
VCC_MAX
VCC_TRANS
-0.7
+20.0
+25.0
V
V
V
(3)
(3)
(9)
-0.3 to +4.2
V
(3)
-0.3 to +3.0
V
(3)
gpms
±2000
g
(3)
Unpowered Shock (six sides, 0.5 ms duration)
gshock
±2500
g
(3)
Drop Shock (to concrete, tile or steel surface, 10 drops, any orientation)
hDROP
1.2
m
(5)
9
10
11
12
Electrostatic Discharge (per AEC-Q100)
External Pins (VCC, IDATA, VSS, VSSA), HBM (100 pF, 1.5 kΩ)
HBM (100 pF, 1.5 kΩ)
CDM (R = 0 Ω)
MM (200 pF, 0 Ω)
VESD
VESD
VESD
VESD
±4000
±2000
±1500
±200
V
V
V
V
(5)
(5)
(5)
(5)
13
14
Temperature Range
Storage
Junction
Tstg
TJ
-40 to +125
-40 to +150
°C
°C
(3)
(9)
15
Thermal Resistance
θJC
2.5
°C/W
(9,14)
2.2
Operating Range
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified.
#
16
17
18
Characteristic
Supply Voltage
Programming Voltage (IDATA ≤ 85 mA)
Applied to IDATA, VCC
Symbol
VL
4.2
Typ
Max
Units
V
V
(1)
(9)
VCC
VCC_UV
VVCC_UV_F
—
—
VH
17.0
VL
VPP
14.0
—
—
V
(3)
TA
TA
TL
-40
-40
⎯
⎯
TH
+105
+125
°C
°C
(1)
(3)
Operating Temperature Range
19
20
Min
MMA51xxKW
Sensors
Freescale Semiconductor, Inc.
5
2.3
Electrical Characteristics - Supply and I/O
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified.
#
Characteristic
Symbol
Min
Typ
Max
Units
21
Quiescent Supply Current
*
IIDLE
4.0
⎯
8.0
mA
(1)
22
Modulation Supply Current
*
IMOD
IIDLE+ 22.0
IIDLE+ 26.0
IIDLE+ 30.0
mA
(1)
23
Inrush Current (Power On until VBUF, VREG, VREGA Stable)
IINRUSH
⎯
⎯
30
mA
(3)
24
25
26
Internally Regulated Voltages
VBUF
VREG
VREGA
VBUF
VREG
VREGA
3.60
2.425
2.425
3.80
2.50
2.50
4.00
2.575
2.575
V
V
V
(1)
(1)
(1)
VVCC_UV_F
VBUF_UV_F
VREG_UV_F
VREGA_UV_F
3.40
2.95
2.15
2.15
3.70
3.15
2.25
2.25
4.0
3.35
2.35
2.35
V
V
V
V
(3, 6)
(3, 6)
(3, 6)
(3, 6)
VCC_HYST
VBUF_HYST
VREG_HYST
VREGA_HYST
0.10
0.05
0.05
0.05
0.25
0.10
0.10
0.10
0.40
0.15
0.15
0.15
V
V
V
V
(3)
(3)
(3)
(3)
ESR
500
0
1000
⎯
1500
200
nF
mΩ
(9)
(9)
VIDLE
ΔVSYNC
⎯
VIDLE+1.4
⎯
VIDLE+2.0
15.4
VIDLE+2.6
V
V
(3, 11)
(3, 6)
ISYNC_PD
⎯
IMOD - IIDLE
⎯
mA
(3)
*
*
*
31
32
33
34
Low Voltage Detection Threshold
VCC Falling
VBUF Falling
VREG Falling
VREGA Falling
Hysteresis
VCC
VBUF
VREG
VREGA
35
36
External Capacitor (VBUF, VREG, VREGA)
Capacitance
ESR (including interconnect resistance)
37
38
Synchronization Pulse (See Figure 5)
VIDLE Voltage Range
DC Sync Pulse Detection Threshold
39
Sync Pulse Pulldown Current
40
Output High Voltage (DO)
ILoad = 100 μA
VOH
VREG - 0.1
⎯
⎯
V
(9)
41
Output Low Voltage (DO)
ILoad = 100 μA
VOL
⎯
⎯
0.1
V
(9)
42
Input High Voltage
CS, SCLK, DI
VIH
0.7 * VREG
⎯
⎯
V
(9)
43
Input Low Voltage
CS, SCLK, DI
VIL
⎯
⎯
0.3 * VREG
V
(9)
44
45
Input Current
High (at VIH) (DI)
Low (at VIL) (CS)
IIH
IIL
-100
10
⎯
⎯
-10
100
μA
μA
(9)
(9)
46
Pulldown Resistance (SCLK)
RPD
20
⎯
100
kΩ
(9)
47
BUS_SW Output High Voltage (BUS_SW)
ILoad = 100 μA
VBUS_SW_OH
3.15
⎯
VBUF
V
(9)
48
Output Low Voltage (BUS_SW)
ILoad = 100 μA
VBUS_SW_OL
0.0
⎯
0.45
V
(9)
49
Daisy Chain Addressing Mode Sync Pulse Period
⎯
tS-S_PM_L
⎯
s
(7)
50
Bus Switch Output Activation Time (C = 50 pF)
From last bit of “SetAdr” Response to 80% of VBUS_SW_OH
⎯
⎯
300
μs
(7)
51
Sync Pulse Blanking Time after “SetAdr” Command Received
From last bit of “SetAdr” Response
s
(7)
27
28
29
30
*
*
tBUS_SW
tDC_BLANKING
200000 / fOSC
MMA51xxKW
6
Sensors
Freescale Semiconductor, Inc.
2.4
Electrical Characteristics - Sensor and Signal Chain
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified.
#
Characteristic
Symbol
Min
Typ
Max
Units
*
*
*
*
SENS
SENS
SENS
SENS
—
—
—
—
8
4
2
1
—
—
—
—
LSB/g
LSB/g
LSB/g
LSB/g
(1)
(1)
(1)
(1)
*
*
ΔSENS_240
ΔSENS_240
ΔSENS_240
ΔSENS_480
ΔSENS_480
ΔSENS_480
-5
-7
-7
-5
-7
-7
—
—
—
—
—
—
+5
+7
+7
+5
+7
+7
%
%
%
%
%
%
(1)
(1)
(9)
(1)
(1)
(9)
*
OFF10Bit
OFF10Bit
-52
-52
0
0
+52
+52
LSB
LSB
(1)
(9)
*
*
OFF10Bit
OFF10Bit
-1
-2
0
0
+1
+2
LSB
LSB
(1)
(9)
56
57
58
59
60
61
Sensitivity (10-bit output @ 100 Hz, referenced to 0 Hz)
±60g Range
±120g Range
±240g Range
±480g Range
Total Sensitivity Error (including non-linearity)
TA = 25°C, ≤ ±240g
TL ≤ TA ≤ TH, ≤ ±240g
TL ≤ TA ≤ TH, ≤ ±240g, VVCC_UV_F ≤ VCC ≤ VL
TA = 25°C, > ±240g
TL ≤ TA ≤ TH, > ±240g
TL ≤ TA ≤ TH, > ±240g, VVCC_UV_F ≤ VCC ≤ VL
62
63
Digital Offset Before Offset Cancellation
10-bit
10-bit, TL ≤ TA ≤ TH, VVCC_UV_F ≤ VCC ≤ VL
64
65
Digital Offset After Offset Cancellation
10-bit, 0.3 Hz HPF or 0.1 Hz HPF
10-bit, 0.04 Hz HPF
66
Continuous Offset Monitor Limit
10-bit output, before compensation
OFFMON
-66
⎯
+66
LSB
(3)
67
Range of Output (10-Bit Mode)
Acceleration
RANGE
-480
⎯
+480
LSB
(3)
68
69
Cross-Axis Sensitivity
X-axis to Z-Axis
Y-axis to Z-Axis
*
*
VXZ
VYZ
-5
-5
⎯
⎯
+5
+5
%
%
(3)
(3)
70
System Output Noise Peak (10-bit Mode, 1 Hz - 1 kHz, All Ranges)
*
nPeak
-4
—
+4
LSB
(3)
71
System Output Noise RMS (10-bit mode, 1 Hz - 1 kHz, All Ranges)
*
nRMS
—
—
+1.0
LSB
(3)
72
73
Non-linearity
10-bit output, ≤ ±240g
10-bit output, > ±240g
NLOUT_240g
NLOUT_480g
-2
-2
⎯
⎯
+2
+2
%
%
(3)
(3)
52
53
54
55
*
*
MMA51xxKW
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Freescale Semiconductor, Inc.
7
2.5
Electrical Characteristics - Self-Test and Overload
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified.
#
Characteristic
Symbol
Min
Typ
Max
Units
gST10_60Z
gST10_120Z
gST10_240Z
gST10_480Z
120
40
35
12
⎯
⎯
⎯
⎯
280
160
153
94
LSB
LSB
LSB
LSB
(3)
(3)
(3)
(3)
74
75
76
77
10-Bit Output During Active Self-Test (TL ≤ TA ≤ TH)
±60g Range
±120g Range
±240g Range
±480g Range
78
79
Acceleration (without hitting internal g-cell stops)
±60g Range Positive
±60g Range Negative
gg-cell_Clip60ZP
gg-cell_Clip60ZN
425
-1205
642
-720
980
-512
g
g
(9)
(9)
80
81
Acceleration (without hitting internal g-cell stops)
±120g Range Positive
±120g Range Negative
gg-cell_Clip120ZP
gg-cell_Clip120ZN
425
-1205
642
-720
980
-512
g
g
(9)
(9)
82
83
Acceleration (without hitting internal g-cell stops)
±240g Range Positive
±240g Range Negative
gg-cell_Clip240ZP
gg-cell_Clip240ZN
1450
-3100
2180
-2210
2800
-1800
g
g
(9)
(9)
84
85
Acceleration (without hitting internal g-cell stops)
±480g Range Positive
±480g Range Negative
gg-cell_Clip480ZP
gg-cell_Clip480ZN
2200
-3700
2800
-3220
3300
-2780
g
g
(9)
(9)
86
87
ΣΔ and Sinc Filter Clipping Limit
±60g Range Positive
±60g Range Negative
gADC_Clip60ZP
gADC_Clip60ZN
159
-334
238
-274
336
-216
g
g
(9)
(9)
88
89
ΣΔ and Sinc Filter Clipping Limit
±120g Range Positive
±120g Range Negative
gADC_Clip120ZP
gADC_Clip120ZN
305
-693
433
-544
577
-414
g
g
(9)
(9)
90
91
ΣΔ and Sinc Filter Clipping Limit
±240g Range Positive
±240g Range Negative
gADC_Clip240ZP
gADC_Clip240ZN
836
-1909
1178
-1566
1599
-1245
g
g
(9)
(9)
92
93
ΣΔ and Sinc Filter Clipping Limit
±480g Range Positive
±480gZ Range Negative
gADC_Clip480ZP
gADC_Clip480ZN
1591
-3217
2014
-2856
2478
-2524
g
g
(9)
(9)
*
*
*
*
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Freescale Semiconductor, Inc.
2.6
Dynamic Electrical Characteristics - PSI5
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified
#
Characteristic
Symbol
Min
Typ
Max
Units
tPSI5_INIT1
tPSI5_INIT2_10s
tPSI5_INIT2_8s
tPSI5_INIT2_10a0
tPSI5_INIT2_8a0
tPSI5_INIT3_10s
tPSI5_INIT3_8s
tPSI5_INIT3_10a0
tPSI5_INIT3_8a0
tOC1
tOC2
tST1
tST2
tST3
ST_RPT
tPME
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
0
⎯
532000 / fOSC
256 * tS-S
288 * tS-S
512 * tASYNC
576 * tASYNC
2 * tS-S
2 * tS-S
19 * tASYNC
2 * tASYNC
320000 / fOSC
280000 / fOSC
128000 / fOSC
128000 / fOSC
128000 / fOSC
⎯
300000 / fOSC
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
5
⎯
s
s
s
s
s
s
s
s
s
s
s
s
s
s
s
(7)
(7)
(7)
(7)
(7)
(7, 12)
(7, 12)
(7, 12)
(7, 12)
(7)
(7)
(7)
(7)
(7)
(7, 12)
(7)
tRS_PM
tRS
tS-S
tSYNC
tSYNC_LPF
tSYNC_LPF_RST_ST
tSYNC_LPF_RST
tSYNC_OFF_500
tA_SYNC_DLY
tPD_DLY
tPD_ON
tSYNC_JIT
58
tPSI5_INIT1
tSYNC_OFF
9
120
⎯
⎯
⎯
50
⎯
⎯
0
⎯
⎯
⎯
⎯
280
66 / fOSC
616 / fOSC
1810 / fOSC
⎯
74 / fOSC
64 / fOSC
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
600
⎯
⎯
2 / fOSC
ms
s
μs
μs
μs
s
s
s
ns
s
s
s
(7)
(7)
(7)
(7)
(9)
(7)
(7)
(7)
(9)
(7)
(7)
(7)
tBIT_LOW
tBIT_HI
7.6000
4.9875
8.0000
5.2500
8.4000
5.5125
μs
μs
(7)
(7)
tRISE
tFALL
324
324
463
463
602
602
ns
ns
(3)
(3)
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
Initialization Timing
Phase 1
Phase 2 (10-Bit, Synchronous Mode, k = 4)
Phase 2 (8-Bit, Synchronous Mode, k = 8)
Phase 2 (10-Bit, Asynchronous Mode 0, k = 8)
Phase 2 (8-Bit, Asynchronous Mode 0, k = 16)
Phase 3 (10-Bit, Synchronous Mode, ST_RPT = 0)
Phase 3 (8-Bit, Synchronous Mode, ST_RPT = 0)
Phase 3 (10-Bit, Asynchronous Mode 0, ST_RPT = 0)
Phase 3 (8-Bit, Asynchronous Mode 0, ST_RPT = 0)
Offset Cancellation Stage 1 Operating Time
Offset Cancellation Stage 2 Operating Time
Self-Test Stage 1 Operating Time
Self-Test Stage 2 Operating Time
Self-Test Stage 3 Operating Time
Self-Test Repetitions
Programming Mode Entry Window
110
111
112
113
114
115
116
117
118
119
120
121
Synchronization Pulse (Figure 5, Figure 28 and Figure 32)
Reset to first sync pulse (Program Mode Entry)
Reset to first sync pulse (Normal Mode)
Sync Pulse Period
Sync Pulse Width
Sync Pulse Reference LPF time constant
Sync Pulse Reference Discharge Start Time
Sync Pulse Reference Discharge Activation Time
Sync Pulse Detection Disable Time (BLANKTIME = 0)
Analog Delay of Sync Pulse Detection
Sync Pulse Pulldown Function Delay Time
Sync Pulse Pulldown Function Activate Time
Sync Pulse Detection Jitter
122
123
Data Transmission Single Bit Time (PSI5 Low Bit Rate)
Data Transmission Single Bit Time (PSI5 High Bit Rate)
124
125
Modulation Current (20% to 80% of IMOD - IIDLE)
Rise Time
Fall Time
126
127
Position of bit transition (PSI5 Low Baud Rate)
Position of bit transition (PSI5 High Baud Rate)
*
*
tBittrans_LowBaud
tBittrans_HighBaud
49
47
50
⎯
51
53
%
%
(7)
(7)
128
Asynchronous Response Time
*
tASYNC
⎯
912 / fOSC
⎯
s
(7)
129
130
131
132
133
134
135
136
Time Slots
Minimum Programmed Time Slot (TIMESLOTx = 0x001)
Maximum Programmed Time Slot (TIMESLOTx = 0x3FF)
Default Time Slot (TIMESLOTx = 0x000)
Time Plot Resolution
Sync Pulse to Daisy Chain Default Time Slot 1
Sync Pulse to Daisy Chain Default Time Slot 2
Sync Pulse to Daisy Chain Default Time Slot 3
Sync Pulse to Daisy Chain Programming Time Slot
*
tTIMESLOTx_MIN
tTIMESLOTx_MAX
tTIMESLOT_DFLT
tTIMESLOTx_RES
tTIMESLOT_DC1
tTIMESLOT_DC2
tTIMESLOT_DC3
tTIMESLOT_DCP
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
2 / fOSC
2046 / fOSC
186 / fOSC
2 / fOSC
186 / fOSC
768 / fOSC
1400 / fOSC
186 / fOSC
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
s
s
s
s/LSB
s
s
s
s
(7, 9)
(3, 7)
(3, 7)
(7)
(7)
(7)
(7)
(7)
Data Interpolation Latency (Figure 35, Figure 36)
Data Setup Time - Synchronous Mode (Figure 36)
Data Setup Time - Double Sample Rate Mode (Figure 37)
Data Setup Time - 16 Bit Resolution Mode (Figure 39)
tLAT_INTERP
tDATASETUP_synch
tDATASETUP_double
tDATASETUP_16
64 / fOSC
48 / fOSC
48 / fOSC
48 / fOSC
⎯
⎯
⎯
⎯
65 / fOSC
56 / fOSC
60 / fOSC
60 / fOSC
s
s
s
s
(7)
(7)
(7)
(7)
Programming Mode Timing
Programming Mode Sync Pulse Period
Programming Mode Command Timeout
OTP Write Command to VCC = VPP
OTP Write CMD Response to OTP programming start
Time to program the OTP User Array
tS-S_PM_L
tPM_TIMEOUT
tPROG_HOLD
tPROG_DELAY
tPROG_ARRAY
495
⎯
⎯
⎯
70
500
4 * tS-S_PM
⎯
⎯
⎯
505
⎯
20
40
⎯
μs
μs
μs
ms
ms
(7)
(7)
(7)
(7)
(7)
137
138
139
140
141
142
143
*
*
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2.7
Dynamic Electrical Characteristics - Signal Chain
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified
#
Characteristic
Symbol
Min
Typ
Max
Units
144
Internal Oscillator Frequency
*
fOSC
3.80
4
4.20
MHz
(1)
145
146
147
148
DSP Low-Pass Filter (Note15)
Cutoff frequency LPF0 (referenced to 0 Hz)
Filter Order LPF0
Cutoff frequency LPF1 (referenced to 0 Hz)
Filter Order LPF1
*
*
*
*
fC_LPF0
OLPF0
fC_LPF1
OLPF1
⎯
⎯
⎯
⎯
400
3
400
4
⎯
⎯
⎯
⎯
Hz
1
Hz
1
(7)
(7)
(7)
(7)
149
150
151
152
153
154
155
156
157
158
159
160
161
162
DSP Offset Cancellation Low-Pass Filter (Note15)
Offset Cancellation Low-Pass Filter Input Sample Rate
Stage 1 Cutoff frequency, Startup Phase 1
Stage 1 Filter Order, Startup Phase 1
Stage 2 Cutoff frequency, Startup Phase 1
Stage 2 Filter Order, Startup Phase 1
Cutoff frequency, Option 0
Filter Order, Option 0
Offset Cancellation Output Update Rate (8-Bit Mode)
Offset Cancellation Output Step Size (8-Bit Mode)
Offset Cancellation Output Update Rate (10-Bit Mode)
Offset Cancellation Output Step Size (10-Bit Mode)
Offset Monitor Update Frequency
Offset Monitor Count Limit
Offset Monitor Counter Size
tOC_SampleRate
fC_OC10
OOC10
fC_OC03
OOC03
fC_OC0
OOC0
tOffRate_8
OFFStep_8
tOffRate_10
OFFStep_10
OFFMONOSC
OFFMONCNTLIMIT
OFFMONCNTSIZE
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
256
10.0
1
0.300
1
0.100
1
fOSC / 2e6
0.125
fOSC / 2e6
0.5
fOSC / 2000
4096
8192
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
μs
Hz
1
Hz
1
Hz
1
s
LSB
s
LSB
Hz
1
1
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
(7)
163
164
165
166
Sensing Element Natural Frequency
±60g
±120g
±240g
±480g
fgcell_Z60
fgcell_Z120
fgcell_Z240
fgcell_Z480
7000
7000
13600
16289
⎯
⎯
⎯
⎯
8000
8000
15100
17996
Hz
Hz
Hz
Hz
(9)
(9)
(9)
(9)
167
168
169
170
Sensing Element Roll-off Frequency (-3 db)
±60g
±120g
±240g
±480g
fgcell_Z60
fgcell_Z120
fgcell_Z240
fgcell_Z480
798
798
2000
2250
⎯
⎯
⎯
⎯
2211
2211
4700
6350
Hz
Hz
Hz
Hz
(9)
(9)
(9)
(9)
171
172
173
174
Sensing Element Damping Ratio
±60g
±120g
±240g
±480g
ζgcell_Z60
ζgcell_Z120
ζgcell_Z240
ζgcell_Z480
1.870
1.870
1.750
1.250
⎯
⎯
⎯
⎯
4.610
4.610
3.500
3.000
⎯
⎯
⎯
⎯
(9)
(9)
(9)
(9)
175
176
177
178
Sensing Element Delay (@100 Hz)
±60g
±120g
±240g
±480g
fgcell_delay_Z60
fgcell_delay_Z120
fgcell_delay_Z240
fgcell_delay_Z480
77
77
40
21
⎯
⎯
⎯
⎯
200
200
86
60
μs
μs
μs
μs
(9)
(9)
(9)
(9)
179
Package Resonance Frequency
fPackage
100
⎯
⎯
kHz
(9)
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2.8
Dynamic Electrical Characteristics - Supply and SPI
VL ≤ (VCC - VSS) ≤ VH, TL ≤ TA ≤ TH, ΔT ≤ 25 K/min, unless otherwise specified
#
Characteristic
Symbol
Min
Typ
Max
Units
tSET
⎯
⎯
5
ms
(3)
tINT_INIT
⎯
16000 / fOSC
⎯
s
(7)
tVCC_MICROCUTmin
tVCC_MICROCUT
tVCC_RESET
30
50
⎯
⎯
⎯
⎯
⎯
⎯
1000
μs
μs
μs
(3)
(3)
(3)
180
Quiescent Current Settling Time (Power Applied to Iq = IIDLE ± 2 mA)
181
Reset Recovery Internal Delay (After internal POR)
182
183
184
VCC Micro-cut (CBUF=CREG=CREGA=1 μF)
Survival Time (VCC disconnect without Reset, CBUF=CREG=CREGA=700 nF)
Survival Time (VCC disconnect without Reset, CBUF=CREG=CREGA=1 μF)
Reset Time (VCC disconnect above which Reset is guaranteed)
185
186
187
188
VBUF, Capacitor Monitor Disconnect Time (Figure 10)
POR to first Capacitor Test Disconnect
Disconnect Time (Figure 10)
Disconnect Delay, Asynchronous Mode (Figure 10)
Disconnect Delay, Synchronous Mode (Figure 11)
tPOR_CAPTEST
tCAPTEST_TIME
tCAPTEST_ADLY
tCAPTEST_SDLY
⎯
⎯
⎯
⎯
12000 / fOSC
1.5
688 / fOSC
72 / fOSC
⎯
5.0
⎯
⎯
s
μs
s
s
(7)
(7)
(7)
(7)
189
190
191
VREG, VREGA Capacitor Monitor
POR to first Capacitor Test Disconnect
Disconnect Time
Disconnect Rate
tPOR_CAPTEST
tCAPTEST_TIME
tCAPTEST_RATE
⎯
⎯
⎯
12000 / fOSC
6 / fOSC
256 / fOSC
⎯
⎯
⎯
s
s
s
(7)
(7)
(7)
192
193
194
195
196
197
198
199
200
201
202
203
204
205
Serial Interface Timing (See Figure 7, CDOUT ≤ 80 pF, RDOUT ≥ 10 kΩ)
Clock (SCLK) period (10% of VCC to 10% of VCC)
Clock (SCLK) high time (90% of VCC to 90% of VCC)
Clock (SCLK) low time (10% of VCC to 10% of VCC)
Clock (SCLK) rise time (10% of VCC to 90% of VCC)
Clock (SCLK) fall time (90% of VCC to 10% of VCC)
CS asserted to SCLK high (CS = 10% of VCC to SCLK = 10% of VCC)
CS asserted to DOUT valid (CS = 10% of VCC to DOUT = 10/90% of VCC)
Data setup time (DIN = 10/90% of VCC to SCLK = 10% of VCC)
DIN Data hold time (SCLK = 90% of VCC to DIN = 10/90% of VCC)
DOUT Data hold time (SCLK = 90% of VCC to DOUT = 10/90% of VCC)
SCLK low to data valid (SCLK = 10% of VCC to DOUT = 10/90% of VCC)
SCLK low to CS high (SCLK = 10% of VCC to CS = 90% of VCC)
CS high to DOUT disable (CS = 90% of VCC to DOUT = Hi Z)
CS high to CS low (CS = 90% of VCC to CS = 90% of VCC)
tSCLK
tSCLKH
tSCLKL
tSCLKR
tSCLKF
tLEAD
320
120
120
⎯
⎯
60
⎯
20
10
0
⎯
60
⎯
1000
⎯
⎯
⎯
15
15
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
40
28
⎯
60
⎯
⎯
⎯
50
⎯
60
⎯
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
tACCESS
tSETUP
tHOLD_IN
tHOLD_OUT
tVALID
tLAG
tDISABLE
tCSN
1. Parameters tested 100% at final test.
2. Parameters tested 100% at wafer probe.
3. Verified by characterization.
4. * Indicates critical characteristic.
5. Verified by qualification testing.
6. Parameters verified by pass/fail testing in production.
7. Functionality guaranteed by modeling, simulation and/or design verification. Circuit integrity assured through IDDQ and scan testing. Timing
is determined by internal system clock frequency.
8. N/A.
9. Verified by simulation.
10. N/A.
11. Measured at VCC pin; VSYNC guaranteed across full VIDLE range.
12. Self-Test repeats on failure up to a ST_RPTMAX times before transmitting Sensor Error Message.
13. N/A.
14. Thermal resistance between the die junction and the exposed pad; cold plate is attached to the exposed pad.
15. Filter cutoff frequencies are directly dependent upon the internal oscillator frequency.
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tRS
ΔVSYNC
tS-S
tSYNC
VIDLE
VSYNC
VCC
GND
Figure 5. Sync Pulse Characteristics
VCC_UV_f + VCC_HYST
VCC_UV_f
VCC
Response Terminated if in process
VBUF_UV_f + VBUF_HYST
VBUF_UV_f
VBUF
VREG_UV_f + VREG_HYST
VREG_UV_f
VREG
VREGA_UV_f+VREGA_HYST
VREGA_UV_f
VREG
POR
Time
Figure 6. Powerup Timing
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CS
tLEAD
tSCLKR
tSCLK
tSCLKF
tCSN
tSCLKH
SCLK
tSCLKL
tLAG
tACCESS
tVALID
tHOLD_OUT
tDISABLE
DOUT
tHOLD_IN
tSETUP
DIN
Figure 7. Serial Interface Timing
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3
Functional Description
3.1
User Accessible Data Array
A user accessible data array allows for each device to be customized. The array consists of an OTP factory programmable
block, an OTP user programmable block, and read only registers for device status. The OTP blocks incorporate independent
error detection circuitry for fault detection (reference Section 3.2). Portions of the factory programmable array are reserved for
factory-programmed trim values. The user accessible data is shown in Table 2.
Table 2. User Accessible Data
Byte
Addr
(XLong
Msg)
Register
$00
SN0
$01
$02
Nibble
Addr
(Long
Msg)
Bit Function
Bit Function
Nibble
Addr
(Long
Msg)
Type
7
6
5
4
3
2
1
0
$01
SN[7]
SN[6]
SN[5]
SN[4]
$00
SN[3]
SN[2]
SN[1]
SN[0]
SN1
$03
SN[15]
SN[14]
SN[13]
SN[12]
$02
SN[11]
SN[10]
SN[9]
SN[8]
SN2
$05
SN[23]
SN[22]
SN[21]
SN[20]
$04
SN[19]
SN[18]
SN[17]
SN[16]
$03
SN3
$07
SN[31]
SN[30]
SN[29]
SN[28]
$06
SN[27]
SN[26]
SN[25]
SN[24]
$04
DEVCFG1
$09
0
0
1
0
$08
1
RNG[2]
RNG[1]
RNG[0]
$05
DEVCFG2
$0B
LOCK_U
PCM
SYNC_PD
LATENCY
$0A
DATASIZE
BLANKTIME
P_CRC
BAUD
$06
DEVCFG3
$0D
TRANS_MD[1] TRANS_MD[0]
LPF[1]
LPF[0]
$0C
TIMESLOTB[9] TIMESLOTB[8] TIMESLOTA[9] TIMESLOTA[8]
$07
DEVCFG4
$0F
TIMESLOTA[7] TIMESLOTA[6] TIMESLOTA[5] TIMESLOTA[4]
$0E
TIMESLOTA[3] TIMESLOTA[2] TIMESLOTA[1] TIMESLOTA[0]
$08
DEVCFG5
$11
TIMESLOTB[7] TIMESLOTB[6] TIMESLOTB[5] TIMESLOTB[4]
$10
TIMESLOTB[3] TIMESLOTB[2] TIMESLOTB[1] TIMESLOTB[0]
F, R
U, R
$09
DEVCFG6
$13
INIT2_EXT
ASYNC
U_DIR[1]
U_DIR[0]
$12
U_REV[3]
U_REV[2]
U_REV[1]
U_REV[0]
$0A
DEVCFG7
$15
MONTH[3]
MONTH[2]
MONTH[1]
MONTH[0]
$14
YEAR[3]
YEAR[2]
YEAR[1]
YEAR[0]
$0B
DEVCFG8
$17
UD[2]
UD[1]
UD[0]
DAY[4]
$16
DAY[3]
DAY[2]
DAY[1]
DAY[0]
$0C
SC
$19
0
TM_B
RESERVED
IDEN_B
$18
OC_INIT_B
IDEF_B
OFF_B
0
R
$0D
MFG_ID
$1B
MFG_ID[7]
MFG_ID[6]
MFG_ID[5]
MFG_ID[4]
$1A
MFG_ID[3]
MFG_ID[2]
MFG_ID[1]
MFG_ID[0]
U, R
Type codes
F: Freescale programmed OTP location
U: User programmable OTP location via PSI5
R: Readable register via PSI5
3.1.1
Device Serial Number Registers
A unique serial number is programmed into the serial number registers of each device during manufacturing. The serial number is composed of the following information:
Bit Range
Content
SN[12:0]
Serial Number
SN[31:13]
Lot Number
Serial numbers begin at 1 for all produced devices in each lot and are sequentially assigned. Lot numbers begin at 1 and are
sequentially assigned. No lot will contain more devices than can be uniquely identified by the 13-bit serial number. Depending on
lot size and quantities, all possible lot numbers and serial numbers may not be assigned.
The serial number registers are included in the factory programmed OTP CRC verification. Reference Section 3.2.1 for details
regarding the CRC verification. Beyond this, the contents of the serial number registers have no impact on device operation or
performance, and are only used for traceability purposes.
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3.1.2
Factory Configuration Register (DEVCFG1)
The factory configuration register is a factory programmed, read only register which contains user specific device configuration
information. The factory configuration register is included in the factory programmed OTP CRC verification.
Location
Bit
Address
Register
$04
DEVCFG1
7
Factory Default
3.1.2.1
6
5
4
3
2
1
0
0
0
1
0
1
RNG[2]
RNG[1]
RNG[0]
0
0
1
0
0
0
0
0
Range Indication Bits (RNG[2:0])
The range indication bits are factory programmed and indicate the full-scale range of the device as shown below.
3.1.3
RNG[2]
RNG[1]
RNG[0]
Full-Scale Acceleration
Range
g-Cell Design
PSI5 Init Data
Transmission (D9)
Reference Table 12
0
0
0
Reserved
N/A
0001
0
0
1
±60g
Medium-g
0111
0
1
0
Reserved
N/A
0010
0
1
1
±120g
Medium-g
1000
1
0
0
Reserved
N/A
0011
1
0
1
±240g
High-g
1001
1
1
0
Reserved
N/A
0100
1
1
1
±480g
High-g
1010
Device Configuration 2 Register (DEVCFG2)
Device configuration register 2 is a user programmable OTP register that contains device configuration information.
Location
Bit
Address
Register
7
6
5
4
3
2
1
0
$05
DEVCFG2
LOCK_U
PCM
SYNC_PD
LATENCY
DATASIZE
BLANKTIME
P_CRC
BAUD
0
0
0
0
0
0
0
0
Factory Default
3.1.3.1
User Configuration Lock Bit (LOCK_U)
The LOCK_U bit allows the user to prevent writes to the user configuration array once programming is completed.
If the LOCK_U bit is written to ‘1’ when a PSI5 “Execute Programming of NVM” command is executed, the LOCK_U OTP bit
will be programmed. Upon completion of the OTP programming, an OTP readout will be executed, locking the array from future
OTP writes. The User Programmable OTP Array Error Detection is also activated (Reference Section 3.2.2).
3.1.3.2
PCM Enable Bit (PCM)
The PCM bit enables the PCM output pin. When the PCM bit is set, the PCM output pin is active and outputs a Pulse Code
Modulated signal proportional to the acceleration response. Reference Section 3.5.3.7 for more information regarding the PCM
output. When the PCM bit is cleared, the PCM output pin is actively pulled low.
PCM
PCM Output
0
Actively Pulled Low
1
PCM Signal Enabled
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3.1.3.3
Sync Pulse Pulldown Enable Bit (SYNC_PD)
The sync pulse pulldown enable bit selects if the sync pulse pulldown is enabled once a sync pulse is detected. Reference
Section 4.2.1.2 for more information regarding the sync pulse pulldown.
SYNC_PD
Sync Pulse Pulldown
0
Disabled
1
Enabled
If Daisy Chain Mode is enabled, the Sync Pulse Pulldown is enabled as listed below:
SYNC_PD
Daisy Chain Address
Programmed
“Run Mode”
Command Received
Daisy Chain Address = ‘001’
Sync Pulse Pulldown
0
x
x
x
Disabled
1
No
x
x
Enabled
1
Yes
No
x
Disabled
1
Yes
Yes
No
Disabled
1
Yes
Yes
Yes
Enabled
3.1.3.4
Latency Selection Bit (LATENCY)
The latency selection bit selects between one of two data latency methods to accommodate synchronized sampling or simultaneous sampling. Reference Section 4.5 for more information regarding latency and data synchronization.
3.1.3.5
Latency
Data Latency
0
Simultaneous Sampling Mode (Latency relative to Sync Pulse)
1
Synchronous Sampling Mode (Latency relative to Time Slot)
Data Size Selection Bit (DATASIZE)
The data size selection bit selects one of two data lengths for the PSI5 response message as shown below.
3.1.3.6
DATASIZE
Data Length
0
10 Bits
1
8 Bits
PSI5 Sync Pulse Blanking Time Selection Bit (BLANKTIME)
The PSI5 sync pulse blanking time selection bit selects the timing for ignoring sync pulses after successful reception of a sync
pulse. Reference Section 4.2.1.1 for details regarding sync pulse detection and blanking.
BLANKTIME
Blanking Time Method
0
Maximum of tSYNC_OFF_500 or Response Transmission Complete
1
Blanking Time determined by end of response transmission for programmed time slot
3.1.3.7
PSI5 Response Message Error Detection Selection Bit (P_CRC)
The PSI5 response message error detection selection bit selects either even parity, or a 3-Bit CRC for error detection of the
PSI5 response message. Reference Section 4.3.3 for details regarding response message error detection.
P_CRC
Parity or CRC
0
Parity
1
CRC
Note: The PSI5 specification recommends parity for data lengths of 10 bits or less.
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3.1.3.8
Baud Rate Selection Bit (BAUD)
The baud rate selection bit selects one of two PSI5 baud rates as shown below. Reference Section 2.6 for baud rate timing
specifications.
3.1.4
BAUD
Baud Rate
0
Low Baud Rate (125 kBaud)
1
High Baud Rate (190.5 kBaud)
Device Configuration Registers (DEVCFG3, DEVCFG4, DEVCFG5)
Device configuration registers 3, 4, and 5 are user programmable OTP registers which contain device configuration
information.
Location
Bit
Address
Register
7
6
5
4
$06
DEVCFG3
TRANS_MD[1]
TRANS_MD[0]
LPF[1]
LPF[0]
$07
DEVCFG4
TIMESLOTA[7] TIMESLOTA[6] TIMESLOTA[5] TIMESLOTA[4] TIMESLOTA[3] TIMESLOTA[2] TIMESLOTA[1] TIMESLOTA[0]
$08
DEVCFG5
TIMESLOTB[7] TIMESLOTB[6] TIMESLOTB[5] TIMESLOTB[4] TIMESLOTB[3] TIMESLOTB[2] TIMESLOTB[1] TIMESLOTB[0]
Factory Default
3.1.4.1
0
0
0
3
2
1
0
TIMESLOTB[9] TIMESLOTB[8] TIMESLOTA[9] TIMESLOTA[8]
0
0
0
0
0
PSI5 Transmission Mode Selection Bits (TRANS_MD[1:0])
The PSI5 transmission mode selection bits select the PSI5 transmission mode as shown below.
TRANS_MD[1]
TRANS_MD[0]
Operating Mode
Reference
0
0
Normal Mode (Asynchronous or Parallel, Synchronous)
Section 4.5.1
0
1
Synchronous Double Sample Rate Mode
Section 4.5.2
1
0
16-bit Resolution Mode (Two 10-bit Responses)
Section 4.5.3
1
1
Daisy Chain Mode
Section 4.5.4
3.1.4.2
Low-Pass Filter Selection Bit (LPF[1:0])
The low-pass filter selection bits select the low-pass filter for the acceleration signal as described below:
3.1.4.3
LPF[1]
LPF[0]
Low-Pass Filter Selected
0
0
400 Hz, 3-Pole
0
1
400 Hz, 4-Pole
1
0
Reserved
1
1
Reserved
TimeSlot Selection Bits (TIMESLOTx[9:0])
The timeslot selection bits select the time slot(s) to be used for data transmission. Reference Section 4.5 for details regarding
PSI5 transmission modes and time slots. Accepted time slot values are 0.5 μs to 511.5 μs in 0.5 μs increments. Care must be
taken to prevent from programming time slots which violate the PSI5 Version 1.3 specification, or time slots which will cause data
contention.
TIMESLOTx[9:0]
ASYNC Bit
Time Slot
Reference
0
Default Time Slot (tTIMESLOT_DFLT) from start of Sync Pulse (tTRIG)
Section 4.5
1
Asynchronous Mode
Section 4.5.1.1
N/A
TimeSlot Definition from start of Sync Pulse (tTRIG) in 0.5μs Increments
Section 4.5
00 0000 0000
Non-Zero
Note: TIMESLOTB is only used for Synchronous Double Sample Rate Mode and 16-Bit Resolution Mode.
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3.1.5
Device Configuration Registers 6, 7, and 8 (DEVCFG6, DEVCFG7, DEVCFG8)
Device configuration registers 6, 7 and 8 are user programmable OTP registers which contain device configuration and user
specific manufacturing information. The user specific manufacturing information bits have no impact on the performance, but are
transmitted during the PSI5 initialization phase 2 in 10-bit mode.
Location
Bit
Address
Register
7
6
5
4
3
2
1
0
$09
DEVCFG6
INIT2_EXT
ASYNC
U_DIR[1]
U_DIR[0]
U_REV[3]
U_REV[2]
U_REV[1]
U_REV[0]
$0A
DEVCFG7
MONTH[3]
MONTH[2]
MONTH[1]
MONTH[0]
YEAR[3]
YEAR[2]
YEAR[1]
YEAR[0]
$0B
DEVCFG8
UD[2]
UD[1]
UD[0]
DAY[4]
DAY[3]
DAY[2]
DAY[1]
DAY[0]
0
0
0
0
0
0
0
0
Factory Default
3.1.5.1
Initialization Phase 2 Data Extension Bit (INIT2_EXT)
The initialization phase 2 data extension bit enables or disables data transmission in data fields D27 through D32 of PSI5 Initialization Phase 2 as shown below.
3.1.5.2
INIT2_EXT
Description
0
D27 through D32 are set to “0000”
1
D27 through D32 are transmitted as defined in Section 4.4.2.1
Asynchronous Mode Bit (ASYNC)
The asynchronous mode bit enables asynchronous data transmission as described in Section 3.1.4.3.
3.1.5.3
User Sensing Direction (U_DIR[1:0])
The user sensing direction registers are user programmable OTP registers which contain the module level sensing direction.
This data is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit mode, as described in Section 4.4.2.1.
U_DIR[1]
U_DIR[0]
Module Sensing Direction
As Defined in AKLV27
PSI5 Init Data Transmission (D8)
Reference Table 12
0
0
Connector Direction (β)
0000
0
1
Bushing Direction (α)
0100
1
0
Perpendicular to α and β (γ)
1000
1
1
Not used
1100
3.1.5.4
User Product Revision (U_REV[3:0])
The user product revision registers are user programmable OTP registers which contain the module production revision. The
device supports up to 16 product revisions. This data is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit
mode, as described in Section 4.4.2.1.
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3.1.5.5
User Production Date Information (YEAR[3:0], MONTH[3:0], DAY[4:0)
The user production date information registers are user programmable OTP registers which contain the module production
date. The table below shows the relationship between the stored values and the production date.
Programmed Value
Decoded Value
Julian Date Value
YEAR[3:0]
Year
JY[6:0]
0000
2009
0001001
•
•
•
•
•
•
•
•
•
1111
2024
0011000
MONTH[3:0]
Month
JM[3:0]
0000
N/A
0000
0001
January
0001
•
•
•
•
•
•
•
•
•
1100
December
1100
•
•
•
•
•
•
•
•
•
1111
N/A
N/A
DAY[4:0]
Day
JD[4:0]
00000
N/A
00000
00001
Day 1
00001
•
•
•
•
•
•
•
•
•
11111
Day 31
11111
The Julian date value is transmitted to the main ECU during PSI5 initialization phase 2 in 10-bit mode, as described in
Section 4.4.2.1.
3.1.5.6
User Specific Data (UD[2:0])
The user specific data bits are user programmable OTP bits. These bits have no impact on device operation or performance.
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3.1.6
Status Check Register (SC)
The status check register is a read-only register containing device status information.
Location
Bit
Address
Register
7
6
5
4
3
2
1
0
$0C
SC
0
TM_B
RESERVED
IDEN_B
OC_INIT_B
IDEF_B
OFF_B
0
3.1.6.1
Test Mode Flag (TM_B)
The test mode bit is cleared if the device is in test mode.
3.1.6.2
TM_B
Operating Mode
0
Test Mode is active
1
Test Mode is not active
Internal Data Error Flag (IDEN_B)
The internal data error bit is cleared if a register data error detection is detected in the user accessible OTP array. A device
reset is required to clear the error.
3.1.6.3
IDEN_B
Error Condition
0
Error detection mismatch in user programmable OTP array
1
No error detected
Offset Cancellation Init Status Flag (OC_INIT_B)
The offset cancellation initialization status bit is set once the offset cancellation initialization process is complete, and the filter
has switched to normal mode.
OC_INIT_B
3.1.6.4
Error Condition
0
Offset Cancellation in initialization
1
Offset Cancellation initialization complete (tOC1 and tOC2 expired)
Internal Factory Data Error Flag (IDEF_B)
The internal factory data error bit is cleared if a register data CRC fault is detected in the factory programmable OTP array. A
device reset is required to clear the error.
3.1.6.5
IDEF_B
Error Condition
0
CRC error in factory programmable OTP array
1
No error detected
Offset Error Flag (OFF_B)
The offset error flag is cleared if the acceleration signal reaches the offset limit.
OFF_B
Error Condition
0
Offset error detected
1
No error detected
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3.1.7
Manufacturer ID (MFG_ID)
The manufacturer ID register is a user programmable OTP register that contains the PSI5 manufacturer ID. The manufacturer
ID register has no impact on the performance, but is transmitted during the PSI5 initialization phase 2 in 10-bit mode.
Location
Bit
Address
Register
7
6
5
4
3
2
1
0
$0D
MFG_ID
MFG_ID[7]
MFG_ID[6]
MFG_ID[5]
MFG_ID[5]
MFG_ID[3]
MFG_ID[2]
MFG_ID[1]
MFG_ID[0]
0
0
0
0
0
0
0
0
Factory Default
MFG_ID
PSI5 Init Data Transmission (D$, D5)
Reference Table 10
0000 0000
D4 = 0100
D5 = 0110
Other
D4 = MFG_ID[7:4]
D5 = MFG_ID[3:0]
3.2
OTP Array CRC Verification
3.2.1
Factory Programmed OTP Array CRC Verification
The Factory programmed OTP array is verified for errors with a 3-bit CRC. The CRC verification is enabled only when the
factory programmed array is locked. The CRC verification uses a generator polynomial of g(x) = X3 + X + 1, with a seed
value = ‘111’.
Once the CRC verification is enabled, the CRC is continuously calculated on all bits in registers $00, $01, $02, $03, and $04
and on the factory programmable device configuration bits with the exception of the factory lock bit. Bits are fed in from right to
left (LSB first), and top to bottom (lower addresses first) in the register map. The calculated CRC is then compared against the
stored 3 bit CRC. If a CRC error is detected in the OTP array, the IDEF_B bit is cleared in the SC register.
The CRC verification is completed on the memory registers which hold a copy of the fuse array values, not the fuse array values.
3.2.2
User Programmable OTP Array Error Detection
The user programmable OTP array is independently verified for errors. The Error Detection is enabled only when the LOCK_U
bit in the user data register array is set.
When a PSI5 Programming Mode “Execute Programming of NVM” command is received and the LOCK_U bit is set, the device
calculates the error detection code and writes the code to NVM, enabling the Error Detection.
Once the error detection is enabled, the error detection code is continuously calculated on all bits in registers $05, $06, $07,
$08, $09, $0A, $0B and $0D with the exception of the LOCK_U bit. The calculated code is then compared against the stored
error code. If a mismatch is detected, the IDEN_B bit is cleared in the SC register.
The error detection is completed on the memory registers which hold a copy of the fuse array values, not the fuse array values.
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3.3
Voltage Regulators
The device derives its internal supply voltage from the VCC and VSS pins. Separate internal voltage regulators are used for the
analog (VREGA) and digital circuitry (VREG). The analog and digital regulators are supplied by a buffer regulator (VBUF) to provide
immunity from EMC and supply dropouts on VCC. External filter capacitors are required, as shown in Figure 1.
The voltage regulator module includes voltage monitoring circuitry which holds the device in reset following power-on until the
internal voltages have increased above the under-voltage detection thresholds. The voltage monitor asserts internal reset when
the external supply or internally regulated voltages fall below the under-voltage detection thresholds. A reference generator provides a reference voltage for the ΣΔ converter.
VCC
VREF
VBUF
VOLTAGE
REGULATOR
VBUF
VREGA = 2.50 V
VOLTAGE
REGULATOR
VREGA
TRIM
BANDGAP
REFERENCE
BIAS
GENERATOR
VREF
TRIM
TRIM
REFERENCE VREF_MOD = 1.250 V
GENERATOR
VBUF
VREF
VREGA
OSCILLATOR
TRIM
ΣΔ
CONVERTER
OTP
ARRAY
VOLTAGE
REGULATOR
VREG = 2.50 V
VREG
DIGITAL
LOGIC
DSP
VCC
COMPARATOR
Micro-cut
VBUF
COMPARATOR
POR
VREG
VREGA
VREF
COMPARATOR
COMPARATOR
Figure 8. Voltage Regulation and Monitoring
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3.3.1
VBUF, VREG, and VREGA Regulator Capacitor
The internal regulators require an external capacitor between each of the regulator pins (VBUF, VREG, or VREGA) and the associated the VSS / VSSA pin for stability. Figure 1 shows the recommended types and values for each of these capacitors.
3.3.2
VCC, VBUF, VREG, and VREGA Under-Voltage Monitor
A circuit is incorporated to monitor the supply voltage (VCC) and all internally regulated voltages (VBUF, VREG, and VREGA). If
any of internal regulator voltages fall below the specified under-voltage thresholds in Section 2, the device will be reset. If VCC
falls below the specified threshold, PSI5 transmissions are terminated for the present response. Once the supply returns above
the threshold, the device will respond to the next detected sync pulse. Reference Figure 9.
VCC micro-cut occurs
VCC
VBUF
VCC under-voltage detected
VREG
VREGA
Response Terminated
IDATA
POR
Time
Figure 9. VCC Micro-Cut Response
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3.3.3
VBUF, VREG, and VREGA Capacitance Monitor
A monitor circuit is incorporated to ensure predictable operation if the connection to the external VBUF, VREG, or VREGA, capacitor becomes open.
In asynchronous mode, the VBUF regulator is disabled tCAPTEST_ADLY seconds after each data transmission for a duration of
tCAPTEST_TIME seconds. If the external capacitor is not present, the regulator voltage will fall below the internal reset threshold,
forcing a device reset.
In synchronous mode, the VBUF regulator is disabled tCAPTEST_SDLY seconds after each sync pulse for a duration of
tCAPTEST_TIME seconds. If the external capacitor is not present, the regulator voltage will fall below the internal reset threshold,
forcing a device reset.
The VREG and VREGA regulators are disabled at a continuous rate (tCAPTEST_RATE), for a duration of tCAPTEST_TIME seconds.
If either external capacitor is not present, the associated regulator voltage will fall below the internal reset threshold, forcing a
device reset.
IDATA
tCAPTEST_TIME
tCAPTEST_ADLY
Capacitor Present
Capacitor Open
CAP_Test
VBUF
VBUF_UV_f
POR
Time
Figure 10. VBUF Capacitor Monitor - Asynchronous Mode
VCC
tCAPTEST_SDLY
tCAPTEST_TIME
tTRIG
CAP_Test
VBUF
Capacitor Present
Capacitor Open
VBUF_UV_f
POR
Time
Figure 11. VBUF Capacitor Monitor - Synchronous Mode
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tCAPTEST_RATE
tCAPTEST_TIME
CAP_Test
VREG
Capacitor Present
Capacitor Open
VPORVREG_f
POR
Time
Figure 12. VREG Capacitor Monitor
tCAPTEST_RATE
tCAPTEST_TIME
CAP_Test
VREGA
Capacitor Present
Capacitor Open
VPORREGA_f
POR
Time
Figure 13. VREGA Capacitor Monitor
3.4
Internal Oscillator
A factory trimmed oscillator is included as specified in Section 2.
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3.5
Acceleration Signal Path
3.5.1
Transducer
The transducer is an overdamped mass-spring-damper system defined by the following transfer function:
where:
2
ωn
H ( s ) = --------------------------------------------------------2
2
s + 2 ⋅ ξ ⋅ ωn ⋅ s + ωn
ζ = Damping Ratio
ωn = Natural Frequency = 2 ∗ Π ∗ fn
Reference Section 2.7 for transducer parameters.
3.5.2
ΣΔ Converter
A sigma delta modulator converts the differential capacitance of the transducer to a 1 MHz data stream that is input to the DSP
block.
g-CELL
α1=
CTOP
VX
FIRST
INTEGRATOR
CINT1
z-1
SECOND
INTEGRATOR
α2
z-1
ΣΔ_OUT
1 - z-1
1 - z-1
CBOT
1-BIT
QUANTIZER
ADC
ΔC = CTOP - CBOT
β1
β2
DAC
V = ΔC x VX / CINT1
V = ±2 × VREF
Figure 14. ΣΔ Converter Block Diagram
3.5.3
Digital Signal Processing Block
A Digital Signal Processing (DSP) block is used to perform signal filtering and compensation. A diagram illustrating the signal
processing flow within the DSP block is shown in Figure 15.
B
A
ΣΔ_OUT
LOW-PASS FILTER
SINC FILTER
DOWNSAMPLING
E
D
C
COMPENSATION
OFFSET
OFFSET CANCELLATION CANCELLATION
LOW-PASS FILTER
OUTPUT
RATE LIMITING
F
OUTPUT
H
G
SCALING
INTERPOLATION OUTPUT
Figure 15. Signal Chain Diagram
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Table 3. Signal Chain Characteristics
A
Description
Sample
Time
(μs)
Data
Width
(Bits)
SD
1
1
Over
Range
(Bits
Signal
Width
(Bits)
Signal
Noise
(Bits)
Signal
Margin
(Bits)
Typical Block Latency
1
Reference
Section 3.5.2
203/fosc
B
SINC Filter
16
20
13
C
Low-Pass Filter
16
26
4
10
3
9
D
Compensation
16
26
4
10
3
9
E
Down Sampling
16
26
4
10
3
9
F
High Pass Filter
16
26
4
10
3
9
Reference Section 3.5.3.2
Section 3.5.3.2
Section 3.5.3.2
68/fosc
Reference Section 3.5.3.3
Section 3.5.3.3
DSP Sampling
G
16
10
4/fosc
Section 3.5.3.5
1
10
64/fosc
Section 3.5.3.5
10-Bit Output Scaling
H
3.5.3.1
Interpolation
Decimation Sinc Filter
The serial data stream produced by the ΣΔ converter is decimated and converted to parallel values by a 3rd order 16:1 sinc
filter with a decimation factor of 16.
3
1 – z –16
H ( z ) = ------------------------------------16 × ( 1 – z – 1 )
Figure 16. Sinc Filter Response, tS = 16 μs
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3.5.3.2
Low-Pass Filter
Data from the Sinc filter is processed by an infinite impulse response (IIR) low-pass filter.
( n 11 ⋅ z 0 ) + ( n 12 ⋅ z – 1 ) + ( n 13 ⋅ z – 2 ) ( n 21 ⋅ z 0 ) + ( n 22 ⋅ z – 1 ) + ( n 23 ⋅ z – 2 )
H ( z ) = a 0 ⋅ ------------------------------------------------------------------------------------------------- ⋅ ------------------------------------------------------------------------------------------------( d 11 ⋅ z 0 ) + ( d 12 ⋅ z – 1 ) + ( d 13 ⋅ z – 2 ) ( d 11 ⋅ z 0 ) + ( d 22 ⋅ z – 1 ) + ( d 23 ⋅ z – 2 )
The device provides the option for one of two low-pass filters. The filter is selected with the LPF[1:0] bits in the DEVCFG3
register. The filter selection options are listed in Section 3.1.4.2. Response parameters for the low-pass filter are specified in Section 2.7. Filter characteristics are illustrated in Figure 17 and Figure 18.
Table 4. Low-Pass Filter Coefficients
Description
Filter Coefficients
Group Delay
a0
5.189235225042199e-02
n11
1.629077582099646e-03
d11
1.0
n12
1.630351547919014e-03
d12
-9.481076477495780e-01
0
d13
0
n21
2.500977520825902e-01
d21
1.0
n22
4.999999235890745e-01
d22
-1.915847097557409e+00
n23
2.499023243303036e-01
d23
9.191065266874253e-01
a0
3.143225986084408e-03
n11
9.951105668343345e-04
d11
1.0
n12
2.003487780064749e-03
d12
-1.892328151433503e+00
400 Hz, 4-Pole LPF n13
1.008466113720278e-03
d13
8.954713774195870e-01
n21
2.516720624825626e-01
d21
1.0
n22
4.999888752940916e-01
d22
-1.918978239761011e+00
n23
2.483390622233452e-01
d23
9.229853042218408e-01
400 Hz, 3-Pole LPF n13
2816/fosc
3392/fosc
Note: Low-Pass Filter values do not include g-cell frequency response.
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Figure 17. Low-Pass Filter Characteristics: fC = 400 Hz, 4-Pole, tS = 16 μs
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Figure 18. Low-Pass Filter Characteristics: fC = 400 Hz, 3-Pole, tS = 16 μs
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3.5.3.3
Offset Cancellation
The device provides an optional offset cancellation circuit to remove internal offset error. A block diagram of the offset cancellation is shown in Figure 19.
INPUT DATA
INC/DEC
OFFSET CANCELLATION
LOW-PASS FILTER
n + ( n ⋅ z–1 )
1
2
a ⋅ ------------------------------------0
d + ( d ⋅ z–1 )
1
2
TO_OUTPUT SCALING
OUT
COUNTER
0.5 Hz (Derived from fOSC)
Input Data downsampled to 256μs
CLK
OFFMONNEG
INC/DEC
OUT
OFF_ERR
UP/DOWN
COUNTER
OFFMONPOS
2 kHz (Derived from fOSC)
OFFMONCNTLIMIT
CLK
Figure 19. Offset Cancellation Block Diagram
The transfer function for the offset LPF is:
no 1 + ( no 2 ⋅ z – 1 )
H ( z ) = ao 0 ⋅ ---------------------------------------------do 1 + ( do 2 ⋅ z – 1 )
Response parameters are specified in Section 2 and the offset LPF coefficients are specified in Table 6.
During startup, two phases of the offset LPF are used to allow for fast convergence of the internal offset error during initialization. The timing and characteristics of each phase are shown in Table 5 and Table 6 and specified in Section 2. For more information regarding the startup timing, reference the PSI5 initialization information in Section 4.4. The offset low-pass filter used in
normal operation is selected by the OC_FILT bit as shown in Table 5.
During the Initialization Self-Test phase, the offset cancellation circuit output value is frozen.
During normal operation, output rate limiting is applied to the output of the high pass filter. Rate limiting updates the offset
cancellation output by OFFStep_xx LSB every tOffRate_xx seconds.
Table 5. Offset Cancellation Startup Characteristics and Timing
Offset Cancellation
Startup Phase
Offset LPF
Output Rate Limiting
Total Time for Phase
1
10 Hz
Bypassed
80 ms
2
0.3 Hz
Bypassed
70 ms
Self-Test
0.3 Hz
Bypassed (Frozen during ST2)
96 ms per Self-Test Sequence (up to 6 repeats)
Complete
0.1 Hz
Enabled
N/A
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Table 6. High Pass Filter Coefficients
Description
10 Hz HPF
0.3 Hz HPF
0.1 Hz HPF
Coefficients
Group Delay
ao0
0.015956938266754
no1
0.499998132328277
do1
1.0
no2
0.499998132328277
do2
-0.984043061733246
ao0
0.000482380390167
no1
0.499938218213271
do1
1.0
no2
0.499938218213271
do2
-0.999517619609833
ao0
0.0001608133316040
no1
0.4999999403953552
do1
1.0
no2
0.4999999403953552
do2
-0.9998391270637512
16.384 ms
537.6 ms
1591ms
Figure 20. 10 Hz Offset Cancellation Low-Pass Filter Characteristics
Figure 21. 0.1 Hz Offset Cancellation Low-Pass Filter Characteristics
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3.5.3.4
Offset Monitor
The device includes an offset monitor circuit. The output of the single pole low-pass filter in the offset cancellation block is
continuously monitored against the offset limits specified in Section 2.4. An up/down counter is employed to count up If the output
exceeds the limits, and to count down if the output is within the limits. The output of the counter is compared against the count
limit OFFMONCNTLIMIT. If the counter exceeds the limit, the OFF_B flag in the SC register is cleared. The counter rails once the
max counter value is reached (OFFMONCNTSIZE). The offset monitor is disabled during Initialization Phase 1, Phase 2, and
Phase 3.
3.5.3.5
Data Interpolation
The device includes 16 to 1 linear data interpolation to minimize the system sample jitter. Each result produced by the digital
signal processing chain is delayed one sample time. On detection of a sync pulse the transmitted data is interpolated from the
2 previous samples, resulting in a latency of one sample time, and a maximum signal jitter of ±1/16 of a sample time. Reference
Section 4.5 for more information regarding interpolation and data latency.
3.5.3.6
Output Scaling
The 26 bit digital output from the DSP is clipped and scaled to a 10-bit or 8-bit word which spans the acceleration range of the
device. Figure 22 shows the method used to establish the output acceleration data word from the 26-bit DSP output.
Over Range
D25
D24
Signal
D23
D22
Noise
D21
D20
D19
D18
D17
D16
D15
D14
8-bit Data Word
D21
D20
D19
D18
D17
D16
D15
D14
10-bit Data Word
D21
D20
D19
D18
D17
D16
D15
D14
D13
D12
D11
D10
Margin
D9
D8
...
D2
D1
D0
Using Rounding
D13
D12
Using Rounding
Figure 22. 10-Bit Output Scaling Diagram
3.5.3.7
PCM Output Function
The device provides the option for a PCM output function. The PCM output is activated if the PCM bit is set in the DEVCFG2
register. When the PCM function is enabled, a 4 MHz Pulse Code Modulated signal proportional to the upper 9 bits of the 10-bit
acceleration response is output onto the PCM pin. The PCM output is intended for test use only.
D[21:13]
Output Scaling
Section 3.5.3.6
A
CARRY
PCM
9
Sample updated every 16μS
9 Bit ADDER
9
B
SUM
fCLK = 4 MHz
9
DD
QQ
DD
QQ
DD
QQ
DDFF
QQ
DFF
Q
FF
FF
FF
FF
FF
FF
FF
CLK
QQ
CLK
CLK
QQ
CLK
CLK
QQ
CLK
CLK
QQ
CLK
CLK
Q
Figure 23. PCM Output Function Block Diagram
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3.6
Overload Response
3.6.1
Overload Performance
The device is designed to operate within a specified range. Acceleration beyond that range (overload) impacts the output of
the sensor. Acceleration beyond the range of the device can generate a DC shift at the output of the device that is dependent
upon the overload frequency and amplitude. The g-cell is overdamped, providing the optimal design for overload performance.
However, the performance of the device during an overload condition is affected by many other parameters, including:
• g-cell damping
• Non-linearity
• Clipping limits
• Symmetry
Figure 24 shows the g-cell, ADC and output clipping of The device over frequency. The relevant parameters are specified in
Section 2.
g-cellRolloff
Acceleration (g)
Region Clipped
by Output
LPFRolloff
R eg
ion
pe
Clip
d by
g-ce
ll
Determined by g-cell
roll-off and ADC clipping
e to
n du arity
o
i
t
r
e
to
in
e
l Dis on-L
lipp
igna and N
nC
S
o
i
f
g
o
Re
etr y
ion
Reg Asymm
gg-cell_Clip
A
d by
gADC_Clip
DC
Determined by g-cell
roll-off and full-scale range
gRange_Norm
Region of Interest
fLPF
Region of No Signal Distortion Beyond
Specification
fg-Cell
5kHz
10kHz
Frequency (kHz)
Figure 24. Output Clipping vs. Frequency
3.6.2
Sigma Delta Modulator Over Range Response
Over Range conditions exist when the signal level is beyond the full-scale range of the device but within the computational
limits of the DSP. The ΣΔ converter can saturate at levels above those specified in Section 2 (GADC_CLIP). The DSP operates
predictably under all cases of over range, although the signal may include residual high frequency components for some time
after returning to the normal range of operation due to non-linear effects of the sensor.
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4
PSI5 Layer and Protocol
4.1
Communication Interface Overview
The communication interface between a master device and the MMA51xx is established via a PSI5 compatible 2-wire interface, with parallel or serial (daisy-chain) connections to the satellite modules. Figure 25 shows one possible system configuration
for multiple satellite modules in parallel.
MASTER DEVICE
SATELLITE MODULE #1
MMA51xx
VCC
VSS
Discrete
Components
VCC_OUT
VSS_OUT
VCC
IData
VSS
SATELLITE MODULE #2
MMA51xx
VCC
VSS
Discrete
Components
VCC_OUT
VSS_OUT
VCC
IData
VSS
Figure 25. PSI5 Satellite Interface Diagram
4.2
Data Transmission Physical Layer
The device uses a two wire interface for both its power supply (VCC), and data transmission. The PSI5 master supplies a preregulated voltage. Data transmissions and synchronization control from the PSI5 master to the device are accomplished via modulation of the supply voltage. Data transmissions from the device to the PSI5 master are accomplished via modulation of the current on the power supply line.
4.2.1
Synchronization Pulse
The PSI5 master modulates the supply voltage in the positive direction to provide synchronization of the satellite sensor data.
Upon reception of a synchronization pulse, the device delays a specified period of time, called a time slot, before transmitting
acceleration data. For more details regarding time slots, refer to Section 3.1.4, and Section 4.5.
SYNC PULSES
VIDLE+ ΔVSYNC
VIDLE
GND
IIDLE + IMOD
IIDLE
Figure 26. Synchronous Communication Overview
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4.2.1.1
Synchronization Pulse Detection
The Synchronization (Sync) pulse detection block generates a valid synchronization pulse signal following the detection of an
externally generated Sync pulse. This signal resets the Sync pulse time reference (tTRIG), and initiates the timers associated with
response messages.
The supply voltage can vary throughout the specified range, so the external Sync pulses may have different absolute voltage
levels. Thus, the Sync pulse detection threshold (VCC_SYNC) is dependent not only on the Sync pulse absolute voltage, but also
on the supply voltage. Figure 27 shows a block diagram of the Sync pulse detection circuit.
VCC
SYNC_OFF
SYNC_OFFSET
R
VSYNC_REF
VSYNC_COMP
D
CONTROL
COUNTER
SYNC_LPF
LOGIC
fOSC/2
SYNC_DET
SYNC_LPF_RESET
SYNC_LPF_RESET
VSS
Figure 27. Synchronization Pulse Detection Circuit
The start of a Sync pulse is detected when the comparator output is set (VSYNC exceeds VSYNC_REF). The comparator output
is input into a counter, and the counter is updated at a fixed frequency of fOSC/2. At a fixed time after the initial sync pulse detection
(tSYNC_LPF_RST_ST), the counter is compared against a limit (the minimum value of tSYNC). If the counter is above the limit, a valid
sync pulse is detected.
If the Sync pulse is valid, the following occur:
1. The valid Sync pulse detection signal is set.
2. The detection counter is reset and disabled for tSYNC_OFF (referenced from tTRIG). tSYNC_OFF is a user
programmable option. Reference Section 3.1.3.6 for details on the selectable option, and Section 2.6 for timing
specifications for each option.
a. If BLANKTIME = ‘0’, tSYNC_OFF = tSYNC_OFF_500
b. If BLANKTIME = ‘1’, tSYNC_OFF=tSYNC_OFF_VAR= tTIMESLOT_DLYx + (2+DATASIZE+(P_CRC?3:1)) *tBIT_x
3. The Sync pulse detection low-pass filter is reset for a specified time (tSYNC_LPF_RESET).
If the Sync pulse is invalid, all timers are reset, and the detector becomes sensitive for the very next fSYNC_DET sample.
The output of the comparator is monitored at the fOSC/2 frequency. Once the comparator output goes high, all of the internal
timers are started, so that the tTRIG jitter is minimized.
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SYNC PULSE
VSYNC_COMP
SYNC_LPF_RESET
SYNC OFF
SYNC_PULSE_PD
RESPONSE
tA_SYNC_DLY
tPD_DLY
tPD_ON
tSYNC_LPF_RST_ST
tTRIG
tSYNC_LPF_RST
tSYNC_OFF_xxx
tTIMESLOTx
Figure 28. Synchronization Pulse Detection Timing
4.2.1.2
Synchronization Pulse Pulldown Function
The device includes an optional Sync pulse pulldown function for systems in which the master device does not include an
active pulldown function. The modulation current pulldown circuit is used, which sinks IMOD-IIDLE additional current from the IDATA
pin. The pulldown current is activated after tPD_DLY (referenced to tTRIG), and is activated for tPD_ON.
4.3
Data Transmission Data Link Layer
4.3.1
Bit Encoding
The device outputs data by modulation of the VCC current using Manchester 2 Encoding. Data is stored in a transition occurring
in the middle of the bit time. The signal idles at the normal quiescent supply current. A logic low is defined as an increase in
current at the middle of a bit time. A logic high is defined as a decrease in current at the middle of a bit time. There is always a
transition in the middle of the bit time. If consecutive “1” or “0” data are transmitted, There will also be a transition at the start of
a bit time.
IMOD CURRENT
IDLE CURRENT
‘0’ BIT
tBIT
‘1’ BIT
SENSED HIGH
SENSED LOW
CONSECUTIVE
‘0’ DATA BITS
CONSECUTIVE
‘1’ DATA BITS
Figure 29. Manchester 2 Data Bit Encoding
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4.3.2
Data Transmission
Transmission frames are composed of two start bits, an 8-Bit or 10-bit data word, and error detection bit(s). Data words are
transmitted least-significant bit (LSB) first. A typical Manchester-encoded transmission frame is illustrated in Figure 30.
Data Bit
SB1
SB0
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
PAR
‘0’
‘0’
‘1’
‘1’
‘1’
‘0’
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
SB1
IMOD
Bit Value
tBIT
tTRAN = tBIT * (2+DATASIZE+(P_CRC?3:1))
tFRAME
Figure 30. Example Manchester Encoded Data Transfer - PSI5-x10P
4.3.3
Error Detection
Error detection of the transmitted data is accomplished via either a parity bit, or a 3-Bit CRC. The type of error detection used
is selected by the P_CRC bit in the DEVCFG register.
4.3.3.1
Parity Error Detection
When parity error detection is selected, even parity is employed. The number of logic ‘1’ bits in the transmitted message must
be an even number.
4.3.3.2
3-Bit CRC Error Detection
When CRC error detection is selected, a 3-bit CRC is appended to each response message. The 3-bit CRC uses a generator
polynomial of g(x) = X3+X+1, with a seed value = ‘111’. Data from the transmitted message is read into the CRC calculator LSB
first, and the data is augmented with three ‘0’s. Start bits are not used in the CRC calculation.Table 7 shows some example CRC
calculation values for 10-bit data transmissions.
Table 7. PSI5 3-Bit CRC Calculation Examples
Data Transmitted
CRC
HEX
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
C2
C1
C0
0x000
0
0
0
0
0
0
0
0
0
0
1
1
0
0x0CC
0
0
1
1
0
0
1
1
0
0
0
1
1
0x151
0
1
0
1
0
1
0
0
0
1
0
0
0
0x1E0
0
1
1
1
1
0
0
0
0
0
0
1
1
0x1F4
0
1
1
1
1
1
0
1
0
0
0
1
0
0x220
1
0
0
0
1
0
0
0
0
0
1
0
0
0x275
1
0
0
1
1
1
0
1
0
1
1
1
1
0x333
1
1
0
0
1
1
0
0
1
1
0
0
1
0x3FF
1
1
1
1
1
1
1
1
1
1
1
0
0
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4.3.4
Data Range Values
Table 9 shows the details for each data range.
Table 8. PSI5 Data Values
8-Bit Data Value
Decimal
10-Bit Data Value
Hex
Decimal
Hex
+511
$1FF
•
•
•
+127
$7F
•
•
•
+502
$1F6
+126
$7E
+501
$1F5
+125
$7D
+500
$1F4
+499
$1F3
•
•
•
•
•
•
+489
$1E9
Description
Reserved
Sensor Defect Error Message
N/A
N/A
+124
$7C
+488
$1E8
Sensor Busy
+123
$7B
+487
$1E7
Sensor Ready
+122
$7A
Sensor Ready, but Unlocked
+486
$1E6
+485
$1E5
N/A
N/A
•
•
•
•
•
•
+121
$79
+481
$1E1
+120
$78
+480
$1E0
•
•
•
•
•
•
•
•
•
•
•
•
+3
$03
+3
$03
+2
$02
+2
$02
+1
$01
+1
$01
0
0
0
0
-1
$FF
-1
$3FF
-2
$FE
-2
$3FE
-3
$FD
-3
$3FD
•
•
•
•
•
•
•
•
•
•
•
•
-120
$88
-480
$220
-121
$87
-481
$21F
•
•
•
•
•
•
•
•
•
•
•
•
-124
$84
-496
$210
-125
$83
-497
$20F
•
•
•
•
•
•
•
•
•
•
•
•
-128
$80
-512
$200
Reserved
Reserved
Maximum positive acceleration value
Positive acceleration values
0g level
Negative acceleration values
Maximum negative acceleration value
Initialization Data Codes
10-Bit Status Data Nibble 1 - 16 (0000 - 1111) (Dx)
8-Bit Status Data Nibble 1 - 4 (00 - 11) (Dx)
Initialization Data IDs
Block ID 1 - 16 (10-bit Mode) (IDx)
Block ID 1 - 4 (8-Bit Mode) (IDx)
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4.4
Initialization
Following powerup, the device proceeds through an initialization process which is divided into 3 phases:
• Initialization Phase 1: No Data transmissions occur
• Initialization Phase 2: Sensor self-test and transmission of configuration information
• Initialization Phase 3: Transmission of “Sensor Busy”, and “Sensor Ready” / “Sensor Defect” message
Once initialization is completed the device begins normal mode operation, which continues as long as the supply voltage remains within the specified limits.
Normal Mode
Sync Pulses
Sync Pulses Ignored or
Program Mode Entry
VIDLE+ ΔVSYNC
...
VIDLE
GND
IIDLE + IMOD
IIDLE
POR
INIT 1
NORMAL MODE
INIT 3
INIT 2
Figure 31. PSI5 Sensor 10-Bit Initialization
During PSI5 initialization, the device completes an internal initialization process consisting of the following:
• Power-on Reset
• Device Initialization
• Program Mode Entry Verification
• Offset Cancellation Initialization (2 Stages)
• Self-Test
Figure 32 shows the timing for internal and external initialization.
POR
Internal
Delay
tINT_INIT
PSI5 Initialization
Phase 1
PSI5 Initialization
Phase 2
tPSI5_INIT1
tPSI5_INIT2
Self-Test
Offset Cancellation Offset Cancellation Raw Offset
Stage 1
Stage 2
Calculation
tOC1
Sync
Pulses
Ignored
tRS_PM
tOC2
tST1
Programming Mode Entry
1) Min. 31 sync pulses
2) PME command
Otherwise
Sync Pulses Ignored
tPME
PSI5
PSI5 Initialization
Normal Mode
Phase 3
tPSI5_INIT3
Self-Test
Self-Test
Deflection Normal Data
Verification Calculation
tST2
tST3
Self-Test
Repeat
(If Necessary)
ST_RPT * tST
No
PM
Entry
PM
Entry
No Transmissions
In Response to
Sync Pulses
tPROG_MODE_START_DELAY
Programming
Mode
Figure 32. Initialization Timing
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4.4.1
PSI5 Initialization Phase 1
During PSI5 initialization phase 1, the device begins internal initialization and self checks, but transmits no data. Initialization
begins with the sequence below and shown in Figure 32:
• Internal Delay to ensure analog circuitry has stabilized (tINT_INIT)
• Offset Cancellation phase 1 Initialization (tOC1)
• Monitor for the Programming Mode Entry Sequence (tPME)
– A sequence of sync pulses received during the program mode entry window in PSI5 initialization phase 1
will allow the device to enter into a PSI5 programming mode if the LOCK_U bit is not set. Reference
Section 5.2 for details.
• Offset Cancellation phase 2 Initialization (tOC2)
• If the Programming Mode Entry Sequence is not detected, the device enters Initialization Phase 2 (tPSI5_INIT2)
4.4.2
PSI5 Initialization Phase 2
During PSI5 initialization phase 2, the device continues it’s internal self checks and transmits the PSI5 initialization phase 2
data. The PSI5 initialization data transmission format varies depending on whether the device is programmed for 8-bit or 10-bit
data. Initialization is transmitted using the initialization data codes and IDs specified in Table 12, and in the order shown in
Figure 33 and Figure 34.
D1
ID11
D11
ID12
D12
D2
...
ID1k
D1k
ID21
D21
Repeat k times
ID22
D22
...
ID2k
D2k
Repeat k times
...
D32
...
ID321 D321 ID322 D322
...
...
ID32k D32k
Repeat k times
Figure 33. PSI5 Initialization Phase 2 Data Transmission Order (10-bit Mode)
D1
ID1H
1
D1H1
ID1H
2
D1H2
D2
...
ID1H
k
Repeat k times
D1Hk
ID1L
1
D1L1
ID1L
2
D1L2
...
...
ID1L
k
Repeat k times
D1Lk
...
D9
ID9L
1
D9L1
...
ID9L
2
D9L2
...
ID9L
k
D9Lk
Repeat k times
Figure 34. PSI5 Initialization Phase 2 Data Transmission Order (8-bit Mode)
The Initialization phase 2 time is calculated with the following equation:
t PHASE2 = TRANS NIBBLE × k × ( DataFields ) × t S – S
where:
• TRANSNIBBLE
• k
• Data Fields
• tS-S
= # of Transmissions per Data Nibble
2 for 10-bit Data: 1 for ID, and 1 for Data
4 for 8-bit Data: 2 for ID, and 2 for Data
= the repetition rate for the data fields
= 32 data fields for 10-bit data, 9 data fields for 8-bit data
= Sync Pulse Period
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4.4.2.1
PSI5 Initialization Phase 2 (10-Bit Mode)
In PSI5 initialization phase 2, 10-bit mode, the device transmits a sequence of sensor specific configuration and serial number
information. The transmission data is in conformance with the PSI5 specification, Revision 1.3 and AKLV27, Revision 1.10. The
data content and transmission format is shown in Table 9 and Table 10. Table 9 shows the 10-bit phase 2 timing for different operating modes. Times are calculated using the equation in Section 4.4.2.
Table 9. Initialization Phase 2 Time (10-Bit Mode)
Operating Mode
Repetition Rate (k)
# of Transmissions
Nominal Phase 2 Time
Asynchronous Mode (228 μs)
8
512
116.7 ms
Synchronous Mode (500 μs)
4
256
128.0 ms
Table 10. PSI5 Initialization Phase 2 Data (10-Bit Mode)
PSI5 V1.2 PSI5 V1.2
Field ID # Nibble ID #
Page
Address
PSI5 Nibble
Address
Register Address
Description
Value
F1
D1
0000
Hard-coded
Protocol Revision = V1.3
0100
F2
D2, D3
0001, 0010
Hard-coded
Number of Data Blocks = 32
0010 0000
F3
D4, D5
0011, 0100
MFG_ID
Manufacturer ID
User
F4
D6, D7
0101, 0110
Hard-coded
Sensor Type = Acceleration (high-g)
0000 0001
0111
U_DIR[1:0] = 00: 0000
U_DIR[1:0] = 01: 0100
U_DIR[1:0] = 10: 1000
U_DIR[1:0] = 11: 1100 (not used)
Axis
User
1000
±60g: 0111
±120g: 1000
±240g: 1001
±480g: 1010
Range
Varies
D8
F5
D9
F6
F7
F8
0
D10
1001
DEVCFG2[7:4]
Sensor Specific Information
User
D11
1010
DEVCFG2[3:0]
Sensor Specific Information
User
D12
1011
Hard-coded
Product Revision
Factory
D13
1100
Hard-coded
Product Revision
Factory
DEVCFG6[3:0]
Product Revision
User
JY[6:3]
User
JY[2:0], JM[3]
User
JM[2:0], JD[1]
User
D14
1101
D15
1110
D16
1111
D17
0000
DEVCFG7[7:0], DEVCFG8[4:0]
converted to
Binary coded Julian Date
Reference Section 3.1.5.5
D18
0001
D19
0010
D20
0011
SN0 (Low Nibble)
MMA51xx Serial Number
Factory
D21
0100
SN1 (High Nibble)
MMA51xx Serial Number
Factory
D22
0101
SN1 (Low Nibble)
MMA51xx Serial Number
Factory
D23
0110
SN2 (High Nibble)
MMA51xx Serial Number
Factory
D24
0111
SN2 (Low Nibble)
MMA51xx Serial Number
Factory
D25
1000
SN3 (High Nibble)
MMA51xx Serial Number
Factory
1001
SN3 (Low Nibble)
MMA51xx Serial Number
Factory
Varies
Varies
D26
SN0 (High Nibble)
1
F9
JD[3:0]
User
MMA51xx Serial Number
Factory
D27
1010
Initial Raw Offset (Offset[3:0])
Raw Offset1
(If INIT2_EXT=1, ‘0000’ otherwise)
D28
1011
Initial Raw Offset (Offset7:4])
Raw Offset1
(If INIT2_EXT=1, ‘0000’ otherwise)
1
D29
1.
1100
([AvgSelfTest[1:0],Offset[9:8]])
Raw Off/Avg ST
(If INIT2_EXT=1, ‘0000’ otherwise)
Self-Test1
Varies
D30
1101
Average Self-Test
(AvgSelfTest[5:2])
Avg
(If INIT2_EXT=1, ‘0000’ otherwise)
Varies
D31
1110
Average Self-Test
(AvgSelfTest[9:6])
Avg Self-Test1
(If INIT2_EXT=1, ‘0000’ otherwise)
Varies
D32
1111
DEVCFG1 [7:4]
Sensor Specific
(If INIT2_EXT=1, ‘0000’ otherwise)
0010
Offset and average self-test data will only be transmitted with sync pulse periods that guarantee the self-test phase1 and phase 2 will be complete prior to
required transmission. If sync pulse periods faster than this are used, ‘0’s will be transmitted instead of offset and/or average self-test data.
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4.4.2.2
Initialization Phase 2 (8-Bit Mode)
In PSI5 initialization phase 2, 8-bit mode, the device transmits a sequence of sensor specific configuration and serial number
information. The transmission data uses a format similar to the PSI5 specification, Revision 1.3 10-bit format modified for 8-bit
transmission. The data content and transmission format is shown in Table 11 and Table 12. Table 11 shows the 8-bit phase 2
timing for different operating modes. Times are calculated using the equation in Section 4.4.2.
Table 11. Initialization Phase 2 Time (8-Bit Mode)
Operating Mode
Repetition Rate (k)
# of Transmissions
Nominal Phase 2 Time
Asynchronous Mode 0 (228 μs)
16
576
131.3 ms
Synchronous Mode (500 μs)
8
288
144.0 ms
Table 12. PSI5 Initialization Phase 2 Data (8-Bit Mode)
PSI5 V1.2 PSI5 V1.2
Page
Field ID # Nibble ID # Address
PSI5 Half-Nibble
Address
Register Address
Description
Value
F1
D1 H
0
00
Hard-coded
Protocol Revision = V1.3
01
F1
D1 L
0
01
Hard-coded
Protocol Revision = V1.3
00
F2
D2 H
0
10
Hard-coded
Number of Data Blocks = 9
00
F2
D2 L
0
11
Hard-coded
Number of Data Blocks = 9
10
F2
D3 H
1
00
Hard-coded
Number of Data Blocks = 9
00
F2
D3 L
1
01
Hard-coded
Number of Data Blocks = 9
00
F3
D4 H
1
10
Hard-coded, MFG_ID[7:6]
Manufacturer ID
F3
D4 L
1
11
Hard-coded, MFG_ID[5:4]
Manufacturer ID
F3
D5 H
2
00
Hard-coded, MFG_ID[3:2]
Manufacturer ID
F3
D5 L
2
01
Hard-coded, MFG_ID[1:0]
Manufacturer ID
F4
D6 H
2
10
Hard-coded
Sensor Type = Acceleration (high-g)
00
F4
D6 L
2
11
Hard-coded
Sensor Type = Acceleration (high-g)
00
F4
D7 H
3
00
Hard-coded
Sensor Type = Acceleration (high-g)
00
F4
D7 L
3
01
Hard-coded
Sensor Type = Acceleration (high-g)
01
F5
D8 H
3
10
F5
D8 L
3
11
U_DIR[1:0] = 00: 0000
U_DIR[1:0] = 01: 0100
U_DIR[1:0] = 10: 1000
U_DIR[1:0] = 11: 1100 (not used)
F5
D9 H
4
00
F5
D9 L
4
01
User
±60g: 0111
±120g: 1000
±240g: 1001
±480g: 1010
User
Axis
User
Varies
Range
Varies
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4.4.3
Internal Self-Test
During PSI5 Initialization Phase 2 and Phase 3, the device completes it’s internal self-test as described below and shown in
Figure 32.
• Self-Test Phase 1 - Raw Offset Calculation
– The average offset is calculated for tST1 (Self-Test Disabled).
– If the INIT2_EXT bit is set, this 10-bit value is transmitted in Initialization Phase 2 (reference Section 4.4.2).
• Self-Test Phase 2 - Self-Test Deflection Verification
–
–
–
–
–
–
The offset cancellation value is frozen for tST2 + 2ms
Self-Test is enabled
After tST2/2, the acceleration output value is averaged for tST2/2 to determine the self-test value
If the INIT2_EXT bit is set, this10-bit value is transmitted in Initialization Phase 2 (reference Section 4.4.2).
The self-test value is compared against the limits specified in Section 2.5
Self-Test is disabled
• Self-Test Phase 3 - Self-Test Normal Data Calculation
– The average offset is calculated for tST3
– If Self-Test passed, the device advances to normal mode
– If Self-Test failed, the device repeats Self-Test Phases 1 through 3 up to ST_RPT times.
4.4.4
Initialization Phase 3
During PSI5 initialization phase 3, the device completes it’s internal self checks, and transmits a combination of “Sensor Busy”,
“Sensor Ready”, or “Sensor Defect” messages as defined in Table 8. The number of messages transmitted in initialization phase
3 varies depending on the mode of operation, and the number of self-test repetitions. Self-Test is repeated on failure up to
ST_RPT times to provide immunity to misuse inputs during initialization. Self-Test terminates successfully after one successful
self-test sequence.
Table 13 shows the nominal Initialization Phase 3 times for different operating modes and self-test repeats. Times are calculated using the following equation.
( t INTINIT + t OC1 + t OC2 + ( t ST1 + t ST2 + t ST3 ) × ( STRPT + 1 ) ) – ( t PSI5INIT1 + t PSI5INIT2xx )
t PSI5INIT3 = ROUNDUP ⎛⎝ --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 2⎞⎠ × t S – S
t
S–S
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Table 13. Initialization Phase 3 Time
Operating Mode
8-Bit Asynchronous Mode 0 (228 μs)
10-Bit Asynchronous Mode 0 (228 μs)
8-Bit Synchronous Mode (500 μs)
10-Bit Synchronous Mode (500 μs)
Self-Test
Repetitions
# of Sensor Busy
Messages
# of Sensor Ready or Sensor
Defect Messages
Nominal Phase 3
Time (ms)
0
0
0.46
1
359
82.31
2
780
178.30
3
1201
274.28
4
1622
370.27
5
2043
466.26
0
2
0.91
1
423
96.90
2
844
192.89
3
1265
288.88
4
1686
384.86
5
2107
480.85
0
0
1
138
2
1.00
70.00
2
330
166.00
3
522
262.00
4
714
358.00
5
906
454.00
0
0
1.00
1
170
86.00
2
362
182.00
3
554
278.00
4
746
374.00
5
938
470.00
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4.5
PSI5 Transmission Modes
4.5.1
Normal Mode
4.5.1.1
Asynchronous Mode
The device can be programmed to respond in asynchronous mode with the following settings:
• TRANS_MD[1:0] = ‘00’ (“Normal Mode”)
• ASYNC = ‘1’ in the DEVCFG6 Register
• TIMESLOTA[9:0] = 0x000 in the DEVCFG3 and DEVCFG4 registers
In asynchronous mode, the device transmits data at a fixed rate (tASYNC) and will not respond to normal sync pulses. However,
during initialization phase 1, sync pulses are monitored to decode the Programming Mode Entry Command and allow entry into
Programming Mode if the LOCK_U bit is not set.
4.5.1.2
Simultaneous Sampling Mode
The device can be programmed to respond in Simultaneous Sampling Mode by setting the TRANS_MD[1:0] bits to “Normal
Mode”, and by programming the LATENCY bit to “Simultaneous Sampling Mode”.
In Simultaneous Sampling Mode, the most recent interpolated acceleration data sample is latched at tTRIG (rising edge of Sync
Pulse) and transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG.
≤ tLAT_INTERP
tTIMESLOTA
Figure 35. Simultaneous Sampling Mode
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4.5.1.3
Synchronous Sampling Mode with Minimum Latency
The device can be programmed to respond in Synchronous Sampling Mode with minimum latency by setting the
TRANS_MD[1:0] bits to “Normal Mode”, and by programming the LATENCY bit to “Synchronous Sampling Mode”.
In Synchronous Sampling Mode, the most recent interpolated acceleration data sample is latched at the time programmed in
TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse). The data is transmitted starting at the time programmed in
TIMESLOTA[9:0], relative to tTRIG.
≤ tLAT_INTERP + tDATASETUP_synch
tTIMESLOTA
Figure 36. Synchronous Sampling Mode with Minimum Latency
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4.5.2
Synchronous Double Sample Rate Mode
The device can be programmed to respond in Synchronous Double Sample Rate Mode with minimum latency by setting the
TRANS_MD[1:0] bits to “Synchronous Double Sample Rate Mode”. The LATENCY bit does not affect operation in this mode.
In Synchronous Double Sample Rate Mode, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse). This data is transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. In addition, the most recent interpolated acceleration data sample is latched at
the time programmed in TIMESLOTB[9:0], relative to tTRIG (rising edge of Sync Pulse) This data is transmitted starting at the time
programmed in TIMESLOTB[9:0], relative to tTRIG.
When Synchronous Double Sample Rate Mode is enabled, PSI5 Initialization data is transmitted in both TIMESLOTA[9:0] and
TIMESLOTB[9:0]. Identical data is transmitted in both Time slots, including the 10-bit resolution Raw Offset and Self-Test Data
in Field 9, D27 though D31 if enabled.
≤tLAT_INTERP+tDATASETUP_double ≤tLAT_INTERP+tDATASETUP_double
tTIMESLOTA
tTIMESLOTB
Figure 37. Synchronous Double Sample Rate Mode
Note: In the event that the programmed values in TIMESLOTA[9:0] and TIMESLOTB[9:0] result in a conflict, no data will be
transmitted in TIMESLOTB[9:0].
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4.5.3
16-Bit Resolution Mode
The device can be programmed to respond in 16-bit Resolution Mode by setting the TRANS_MD[1:0] bits to “16-bit Resolution
Mode”. In this mode, the 26 bit digital output from the DSP is clipped and scaled to a 16-bit word. Figure 38 shows the method
used to establish the 16-bit data word from the 26 bit DSP output.
Over Range
Signal
Noise
D25 D24 D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9
16-bit Data Word
D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9
Margin
D8
D7
D6
D8
D7
D6
D5
...
D2
D1
D0
Using Rounding
Figure 38. 16-Bit Output Scaling Diagram
16-Bit Resolution Mode can be programmed to operate in either “Simultaneous Sampling Mode”, or “Synchronous Sampling
Mode”, by setting the LATENCY bit to the desired operating mode. In Simultaneous Sampling Mode, the most recent interpolated
acceleration data sample is latched at tTRIG (rising edge of Sync Pulse). In Synchronous Sampling Mode, the most recent interpolated acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync
Pulse).
The most significant 10 bits (D[21:12]) are truncated and transmitted starting at the time programmed in TIMESLOTA[9:0], relative to tTRIG. The 16-bit value is then clipped to ±480 counts, and the least significant 10 bits (D15:D6) are transmitted starting
at the time programmed in TIMESLOTB[9:0], relative to tTRIG.
When 16-Bit Resolution Mode is enabled, PSI5 Initialization data is transmitted in both TIMESLOTA[9:0] and
TIMESLOTB[9:0]. Identical data is transmitted in both Time slots, including the 10-Bit Resolution Raw Offset and Self-Test Data
in Field 9, D27 though D31 if enabled.
tTIMESLOTA
tTIMESLOTB
≤tLAT_INTERP + tDATASETUP_16
Figure 39. 16-Bit Resolution Mode with Synchronous Sampling
Note: In the event that the programmed values in TIMESLOTA[9:0] and TIMESLOTB[9:0] result in a conflict, no data will be
transmitted in TIMESLOTB[9:0].
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4.5.4
Daisy Chain Mode
The device can be programmed to operate in Daisy Chain Mode by setting the TRANS_MD[1:0] bits to “Daisy Chain Mode”.
Daisy Chain Mode can be programmed to operate in either “Simultaneous Sampling Mode”, or “Synchronous Sampling Mode”
by setting the LATENCY bit to the desired operating mode. In Simultaneous Sampling Mode, the most recent interpolated acceleration data sample is latched at tTRIG (rising edge of Sync Pulse). In Synchronous Sampling Mode, the most recent interpolated
acceleration data sample is latched at the time programmed in TIMESLOTA[9:0], relative to tTRIG (rising edge of Sync Pulse).
When programmed to operate in Daisy Chain Mode, the procedure below is followed:
• On powerup, the device proceeds through normal PSI5 initialization as specified in Section 4.4 using a predefined
time slot tTIMESLOT_DCP.
• Upon successful completion of Initialization Phase 3, including the 2 “Sensor Ready” or Sensor Defect”
messages, responses to sync. pulses are terminated and the device waits for a PSI5 “Set Address” command
defined in Table 14 and Table 15.
– The Daisy Chain Programming command and response formats are defined in Section 5.4.
– Valid Daisy Chain Addresses are defined in Table 16.
– The response to the PSI5 Set Address command uses the predefined time slot tTIMESLOT_DCP.
• After receiving a valid address and completing the response, sync. pulses are blanked for tDC_BLANKING. Once
the blanking time expires, the device does not respond to any sync. pulses until a “Run Mode” command is
received, as defined in Table 14 and Table 15.
• When the “Run Mode” command is received, the device responds to this command using the programmed daisy
chain time slot. All commands are then ignored, and sync pulses are responded to with acceleration data using
the following response format, regardless of the state of the relevant bits in the Device Configuration Registers:
Parameter
Reference
Value
Default time slot specified in Table 16
Time Slot
Section 3.1.4.3
Data Size
Section 3.1.3.5
10-bit data
Error Checking
Section 3.1.3.7
Even Parity
Baud Rate
Section 3.1.3.8
Low Baud Rate: 125 kBaud
• During initialization and Run Mode, the Sync pulse pulldown is enabled as specified in Section 3.1.3.3.
Table 14. Daisy Chain Programming Commands and Responses
SAdr
FC
Response (OK)
Response (Error)
#
CMD
Type
A2
A1
A0
F2
F1
F0
RC
RD1
RC
RD1
D0
Short
0
0
0
A2
A1
A0
Set Sensor Address (Daisy Chain)
OK
SAdr
Error
ErrN
D1
Short
1
1
1
0
0
0
Broadcast Message - “Run Mode”
OK
0x000
Error
ErrN
Command
Table 15. Daisy Chain Programming Response Code Definitions
Response Code
Definition
Value
RC = OK
Command Message Received Properly
0x1E1
RC = Error
Error during transmission of Command Message
0x1E2
SAdr
Programmed Sensor Address, prepended with 0s
Varies
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Table 16. Valid Daisy Chain Addresses
Sensor Address
(SAdr)
A2
A1
A0
Description
Bus Switch Control
Default Time Slot
0
0
0
Address of unprogrammed sensor
N/A
N/A
0
0
1
Sensor Address 1
CLOSED
tTIMESLOT_DC1
0
1
0
Sensor Address 2
CLOSED
tTIMESLOT_DC2
0
1
1
Sensor Address 3
CLOSED
tTIMESLOT_DC3
1
0
0
Sensor Address 4
OPEN
tTIMESLOT_DC1
1
0
1
Sensor Address 5
OPEN
tTIMESLOT_DC2
1
1
0
Sensor Address 6
OPEN
tTIMESLOT_DC3
1
1
1
Global Address for Broadcast Message to all Sensors
N/A
N/A
4.6
Error Handling
4.6.1
Sensor Defect Message
The following failures will cause the device to transmit a “Sensor Defect” error message:
4.6.2
Error Condition
Error Type
Offset Error
Temporary (Normal transmissions continue once offset returns within limits)
Self-Test Failure
Latched until reset
IDEN_B, IDEF_B flag cleared
Latched until reset
No Response Error
The following failures will cause the device to stop transmitting:
Error Condition
Error Type
Under-Voltage Failure (VCC)
Temporary: Normal transmissions continue once voltage returns above failure limit)
Under- / Over-Temperature Failure
Temporary: Normal transmissions continue once temperature returns within the specified limits)
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5
Programming Mode Via PSI5
5.1
Introduction
Programming mode via PSI5 is a synchronous communication mode that allows for bidirectional communication with the device. Programming mode is intended for factory programming of the OTP array. It is not intended for use in normal operation.
5.2
Programming Mode Via PSI5 Entry
The device enters programming mode if and only if the following sequence occurs:
• The device is unlocked (the LOCK_U bit in the DEVCFG2 register is ‘0’).
• At least 31 sync pulses are detected, directly preceding the Programming Mode Entry Short Command during the
Programming Mode Entry Window shown in Figure 32.
– The window timing is defined in Section 2.6 (tPME).
– The Sync pulses and Programming Mode Entry command must be received with a sync pulse period
of tS-S_PM_L
If the Programming Mode entry requirement is not met:
• Programming Mode Entry is blocked until the device is Reset.
• The device proceeds with PSI5 Initialization Phase 2, and PSI5 Initialization Phase 3.
• The device enters normal mode, and responds as programmed to normal sync pulses.
If the Programming Mode entry requirement is met:
• Normal transmissions to sync pulses are terminated.
• After a predefined Start Delay, the device begins to decode PSI5 Short and Long Commands.
• The device responds only to valid PSI5 Short and Long Commands addressed to Sensor Address ‘001’, as
defined in Table 18.
Note: The sync pulse pulldown is disabled in the Programming Mode Entry Window regardless of the state of the SYNCPD bit.
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5.3
Programming Mode Via PSI5 - Data Link Layer
5.3.1
Programming Mode Via PSI5 - Command Bit Encoding
Commands messages are transmitted via the modulation of the supply voltage. The presence of a sync pulse is a logic '1' and
the absence of a sync pulse is a logic '0'. Sync pulses are expected at a rate of tS-S_PM_L.
5.3.2
Programming Mode Via PSI5 - Command Message Format
Command message data frames consist of a start condition, 3 Start Bits (S[2:0]), a 3 bit Sensor Address (SAdr[2:0]), a 3-bit
Function Code (FC[2:0]), an optional Register Address (RAdr[5:0]), an optional data field (D[3:0]), and a 3-bit CRC (C[2:0]. The
start condition consists of one of the following:
1. A minimum of 5 consecutive logic ‘0’s (with not sync bits)
2. A minimum of 31 consecutive logic ‘1’s
The command message format is shown in Figure 41.
Start Bits
Sensor Address
Function Code
Register Address
Data
CRC
Response
S2
S1
S0
SA0
SA1
SA2
FC0
FC1
FC2
RA0
RA1
RA2
RA3
RA4
RA5
D0
D1
D2
D3
C2
C1
C0
0
1
0
1
0
0
0
1
0
0
0
0
0
0
0
1
1
1
1
0
0
0
RC
RD1
RD0
$3FF $3FF $3FF
CRC
Data to be written to register (optional)
Register Address (optional)
Function Codes for MMA51xx (Reference Section 5.3.6)
Sensor Address - Fixed at 001 for MMA51xx
Start Bit Sequence = 010
Figure 40. Programming Mode Via PSI5 Command Data Format
Bit stuffing is necessary to maintain a synchronized time base between the command master and the device. A logic ‘1’ Sync
bit is added every 4th bit in the command message to ensure there will never be more than 3 logic '0' bits in a row.
Sensor
Address
Start Bits
Function Code
Register Address
Data
CRC
Response
S2 S1 S0 Sy SA0 SA1 SA2 Sy FC0 FC1 FC2 Sy RA0 RA1 RA2 Sy RA3 RA4 RA5 Sy D0 D1 D2 Sy D3 C2 C1 Sy C0
0
1
0
1
1
0
0
1
0
0
0
1
0
0
0
1
0
0
0
1
1
1
1
1
1
0
0
1
0
RC
RD1
RD0
$1E2
$3FF
$3FF
Figure 41. Programming Mode Via PSI5 Command Data Format with Sync Bits
Once a command is received and verified, the device expects 2 to 3 consecutive sync pulses (depending upon the command
message lengths described below). For each of these sync pulses, the device will respond with the following settings:
Parameter
Register Bits
Reference
Value
Time Slot
N/A
N/A
tTIMESLOT_DC1
Data Size
DATASIZE = 0
Section 3.1.3.5
10-bit data
Error Checking
P_CRC = 0
Section 3.1.3.7
Even Parity
Baud Rate
BAUD
Section 3.1.3.8
125 kBaud
Sync Pulse Pulldown
SYNCPD
Section 3.1.3.3
Disabled
Figure 42. Programming Mode Via PSI5 Response Message Settings
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5.3.2.1
Short Frame Command and Response Format
Short frames are the simplest type of command message. No data is transmitted in a short frame command. Only specific
instructions are performed in response to short frame commands. The Short Frame format is shown in Figure 43. Short Frame
commands and responses are defined in Section 5.3.6, Table 18.
Sensor
Address
Start Bits
S2
S1
S0
Sy
0
1
0
1
Function Code
SA0 SA1 SA2 Sy
1
0
0
CRC
FC0 FC1 FC2 Sy
1
0
0
1
1
Response
C2
C1
C0
RC
RD1
0
0
0
$1E2
$3FF
Figure 43. Programming Mode Via PSI5 Short Command and Response Format
5.3.2.2
Long Frame Command and Response Format
Long frames allow for the transmission of data nibbles for register writes. The device can provide register data in response to
a read or write request. The Long Frame format is shown in Figure 44. Long Frame commands and responses are defined in
Section 5.3.6.
Sensor
Address
Start Bits
Function Code
Register Address
Data
CRC
Response
S2 S1 S0 Sy SA0 SA1 SA2 Sy FC0 FC1 FC2 Sy RA0 RA1 RA2 Sy RA3 RA4 RA5 Sy D0 D1 D2 Sy D3 C2 C1 Sy C0
0
1
0
1
1
0
0
1
0
1
0
1
0
0
0
1
0
0
0
1
1
1
1
1
1
0
0
1
0
RC
RD1
RD0
$1E2
$3FF
$3FF
Figure 44. Programming Mode Via PSI5 Long Command and Response Format
5.3.3
Command Message CRC
Programming mode command error checking is accomplished by a 3-bit CRC. The 3-bit CRC is calculated using all message
bits except start bits and sync bits. The CRC verification uses a generator polynomial of g(x) = X3+X+1, with a seed value = ‘111’.
The data is provided to the CRC calculator in the order received (LSB first, SAdr, FC, RAdr, Data), and then augmented with three
‘0’s. Table 8 shows some example CRC calculation values for 10-bit data transmissions.
The calculated CRC is then compared against the received 3-bit CRC (received MSB first). If a CRC mismatch is detected,
the device responds with a CRC Error response as defined in Section 5.3.7.
5.3.4
Command Sync Pulse Blanking Time
In Programming Mode and Programming Mode Entry, the device employs a fixed Sync Pulse blanking time of tSYNC_OFF_500
regardless of the state of the BLANKTIME bit.
5.3.5
Command Timeout
In the event that the device does not detect a sync pulse within a 4-bit window time (missing sync bit), the command reception
will be terminated and the device will respond to the next sync pulse with a Short Frame Framing Error response as defined in
Section 5.3.7.
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5.3.6
Programming Mode Via PSI5 Command and Response Summary
Table 17. Programming Mode Via PSI5 Commands and Responses
CMD
Type
#
S0
SAdr
Short
FC
Command
100
Execute Programming of NVM
Response (OK)
Response (Error)
Register
Address
Data
Field
RC
RD1
RD0
RC
RD1
RD0
N/A
N/A
OK
0x2AA
N/A
Error
ErrN
N/A
S1
Short
101
Invalid Command
N/A
N/A
No Response
No Response
S2
Short
110
Invalid Command
N/A
N/A
No Response
No Response
S3
Short
111
Enter Programming Mode
N/A
N/A
OK
0x0CA
N/A
001
No Response
LR
Long
010
Read nibble located at address
RA5:RA0
Varies
Varies
OK
RData
RData+1
Error
ErrN
0x000
LW
Long
011
Write nibble to register RA5:RA0
Varies
Varies
OK
WData
RA5:RA0 Error
ErrN
0x000
XLR XLong
000
Invalid Command
Any
Any
No Response
No Response
XLW XLong
001
Invalid Command
Any
Any
No Response
No Response
Note: When reading the last address in the data array, RData+1 will always return 0x00.
Table 18. Programming Mode Via PSI5 Response Code Definitions
Response Code
Definition
Value
RC = OK
Command Message Received Properly
0x1E1
RC = Error
Error during transmission of Command Message
0x1E2
RData
Byte Contents of Register located at Byte address in which nibble address RA5:RA0 falls in.
(Example: For RA5:RA0 = $04 - RData = Data at Byte Address $02)
Varies
RData + 1
Byte Contents of Register located at Byte address in which nibble address RA5:RA0 +2 falls in.
(Example: For RA5:RA0 = $04 - RData + 1= Data at Byte Address $03)
Varies
WData
Byte Contents of Register located at Byte address in which nibble address RA5:RA0 falls
in after write operation. (Example: For RA5:RA0 = $04 - RData = Data at Byte Address $02)
Varies
5.3.7
Programming Mode Via PSI5 Error Response Summary
Table 19. Error Response Summary
ErrN*
Mnemonic
Description
Supported By MMA51xx
0000
General
General Error
No
0001
Framing
Framing Error
Yes
0010
CRC
CRC Error on Received Message
Yes
0011
Address
Sensor Address Not Supported
No (Invalid Address is ignored)
0100
FC
Function Code Not Supported
No (N/A)
0101
Data Range
Unsupported Register Address
Yes
0110
Write Protect
Destination Address is Write protected (Locked)
Yes
0111
Reserved
Reserved
No
Reserved
Reserved
No
1000
1001
1010
1011
1100
1101
1110
1111
* ErrN is transmitted in the 4 LSBs of RD1. All other bits in the response data field are set to ‘0’.
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5.4
OTP Programming Via PSI5 Procedure
1. Enter Programming Mode.
2. Load desired data into the OTP shadow registers using PSI5 Long Write commands.
3. Send “Execute Programming of NVM“Short command.
4. Set VCC = VPP prior to, or within tPROG_HOLD after the “Execute Programming of NVM” Command has been
transmitted. There is an internal delay of tPROG_DELAY after the “Execute Programming of NVM” Command is
received until the OTP programming begins.
5. Delay a minimum of tPROG_USER. During the OTP Write sequence, sync pulses will be ignored. However,
transmission of sync pulses during the OTP Write sequence should be prevented.
6. Read the SC register and verify IDEF_B flag is set (indicating the write is complete and successful, and the shadow
registers have been refreshed with the OTP contents).
7. Read the OTP register values and compare to the desired values.
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6
SPI Diagnostic and Programming Mode
SPI Diagnostic and Programming Mode allows for the following functions:
• Programming of the OTP array
• Reading of memory registers
SPI transfers follow CPOL = 0, CPHA = 0, MSB first convention. Figure 7 shows the SPI transfer timing, and Figure 45 shows
the SPI transfer protocol.
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
SCLK
CS
DIN
DOUT
D15
D14
Figure 45. SPI Transfer Protocol
The following operations are supported in DPM:
• Register pointer write
• Register pointer read
• Register data write
• Register data read
• Acceleration data read
6.1
Communication Error Detection
6.1.1
Data Input Parity Detection
All commands except for the DPM Entry command employ odd parity to ensure data integrity. For Read commands, the parity
bit is located in bit D10, and the parity is calculated using bits D15 through D11. For Write commands, the parity bit is located in
bit D9, and the parity is calculated using bits D15 through D0. If a parity error is detected, both the current and subsequent commands are ignored, and the parity fault response is transmitted during the subsequent SPI transfer.
6.1.2
Data Output Parity
All responses except for the DPM entry response employ odd parity to ensure data integrity. Parity is calculated using the entire
16-bit message.
6.2
DPM Entry
DPM can be activated at any time during the operation of the device, provided the SPI DPM Entry command is the first command transmitted. If an incorrect DPM Entry command is received, DPM is locked out, and cannot be activated until the device
is reset.
The device responds to the DPM Entry command with the logical complement of the received data as confirmation that it has
been received correctly. Upon completion of a successful transfer DPM is activated. Once activated, the device will remain in
DPM until a reset condition occurs.
Following successful transmission of the DPM Entry command, DPM operations may be completed in any order.
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6.3
DPM Command/Response Summary
Table 20 provides a summary of SPI commands and responses.
Table 20. SPI Command/Response Summary
Command
SPI DPM Entry
Register Pointer Write
Register Pointer Read
Register Data Write
Register Data Read
Acceleration Data Read
Invalid Command Response
(Waiting for SPI DPM Entry)
Invalid Command Response
Parity Fault Response
(Subsequent Message Response)
6.4
Pin
Bit
D15 D14 D13 D12 D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DIN
1
0
1
0
0
0
1
1
0
1
0
1
1
1
0
0
DOUT
0
1
0
1
1
1
0
0
1
0
1
0
0
0
1
1
DIN
0
1
0
0
1
1
P
X
A7
A6
A5
A4
A3
A2
A1
A0
DOUT
1
0
1
1
0
P
0
1
0
0
0
0
0
0
0
0
DIN
0
1
0
0
0
P=0
0
X
X
X
X
X
X
X
X
X
DOUT
1
0
1
1
0
P
0
1
A7
A6
A5
A4
A3
A2
A1
A0
DIN
0
1
0
1
1
0
P
X
D7
D6
D5
D4
D3
D2
D1
D0
DOUT
1
0
1
0
0
P
1
0
A7
A6
A5
A4
A3
A2
A1
A0
DIN
0
1
0
1
0
P=1
0
X
X
X
X
X
X
X
X
X
DOUT
1
0
1
0
0
P
1
0
D7
D6
D5
D4
D3
D2
D1
D0
DIN
0
1
1
0
0
P=1
0
0
0
0
0
0
0
0
0
0
DOUT
1
0
0
1
1
P
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DIN
0
0
D[13] D[12] D[11] D[10] D[9]
D[8]
D[7]
D[6]
D[5]
D[4]
D[3]
D[2]
D[1]
D[0]
DOUT
1
D[2]
D[1]
D[0]
D[2]
D[1]
D[0]
DIN
0
DOUT
1
No Response (all 0s) - DPM Entry Locked Out
1
1
D[12] D[11] D[10] D[9]
D[8]
D[7]
D[6]
D[5]
D[4]
D[3]
No Response (all 0s) - DPM Entry Locked Out
DIN
1
1
DOUT
0
0
DIN
1
0
D[13] D[12] D[11]
...
D[x]
Not SPI DPM Entry Command
DOUT
0
1
D[13] D[12] D[11]
...
D[x]
No Response (all 0s) - DPM Entry Locked Out
DIN
X
X
X
X
D[13] D[12] D[11] D[10] D[9]
D[8]
D[7]
D[6]
D[5]
D[4]
D[3]
No Response (all 0s) - DPM Entry Locked Out
X
X
X
DOUT d[15] d[14] d[13] d[12] d[11] d[10] d[9]
X
X
X
X
X
X
X
X
X
d[8]
d[7]
d[6]
d[5]
d[4]
d[3]
d[2]
d[1]
d[0]
DIN
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
DOUT
1
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
Register Pointer Operations
Access to internal registers is accomplished via a pointer register. The pointer contains the address of the register affected by
register data write and read operations. Two register pointer operations are provided: Register Pointer Write, and Register Pointer
Read. Command and response information is shown in Table 20.
6.5
Register Data Operations
Two register operations are provided: Register Write, and Register Read. In each case, the address of the affected register is
contained in the register pointer.
6.5.1
Register Write Command
The Register Write command format is shown in Table 20. The least significant 8 bits of the Register Write command message
contain the data to be written to the register pointed to by the register pointer. The least significant 8 bits of the Register Write
response message contain the address of the register that was modified.
The write to the register is executed during the clock cycle immediately after CS is deasserted.
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6.5.2
Register Read Command
The Register Read command format is shown in Table 20. The least significant 8 bits of the Register Read command message
are ignored. The least significant 8 bits of the Register Read response message contain the contents of the register pointed to
by the register pointer.
16 bit register reads are possible using consecutive Register Read commands. The high byte of a 16 bit register will automatically be frozen on a read of the low byte of the register.
6.5.3
Acceleration Data Read Operations
The Acceleration Data Read command format is shown in Table 20. The response to this command provides either 8-bit, or
10-bit acceleration data depending on the state of the DATASIZE bit in the DEVCFG2 register.
DATASIZE
6.5.4
6.5.4.1
Bit
D15 D14 D13 D12 D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DATASIZE = 1 (8-Bit Data)
1
0
0
1
1
P
0
0
D7
D6
D5
D4
D3
D2
D1
D0
DATASIZE = 0 (10-Bit Data)
1
0
0
1
1
P
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Error Responses
Response to Invalid Commands
Reference Table 20 for responses to Invalid Commands.
6.5.4.2
Parity Fault Response
If the device detects a Command Parity fault, the current, and subsequent SPI commands are ignored and the device responds
to the subsequent message with the Parity Fault response, as shown in Table 20.
6.6
SPI OTP Programming Procedure
1. Set VCC = VPP.
2. Enter SPI DPM.
3. Load desired data into the OTP shadow registers using SPI Write commands.
a. Write the desired contents of DEVCFG2 ($05) to address $05
b. Write the desired contents of DEVCFG2 ($05) to address $1E
c. Write the desired contents of DEVCFG3 ($06) to address $06
d. Write the desired contents of DEVCFG3 ($06) to address $1F
e. Write the desired contents of DEVCFG4 ($07) to address $07
f. Write the desired contents of DEVCFG4 ($07) to address $20
g. Write the desired contents of DEVCFG5 ($08) to address $08
h. Write the desired contents of DEVCFG5 ($08) to address $21
i. Write the desired contents of DEVCFG6 ($09) to address $09
j. Write the desired contents of DEVCFG6 ($09) to address $22
k. Write the desired contents of DEVCFG7 ($0A) to address $0A
l. Write the desired contents of DEVCFG7 ($0A) to address $23
m.Write the desired contents of DEVCFG8 ($0B) to address $0B
n. Write the desired contents of DEVCFG8 ($0B) to address $24
o. Write the desired contents of MFG_ID ($0D) to address $0D
p. Write the desired contents of MFG_ID ($0D) to address $2E
4. Write 0x05 to register $44 to initiate the NVM programming.
5. Delay a minimum of tPROG_ARRAY
6. Read the SC register and verify the IDEF_B flag is set (indicating the write is complete and successful).
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7
Package
7.1
Case Outline Drawing
Reference Freescale Case Outline Drawing # 98ASA00090D
http://www.freescale.com/files/shared/doc/package_info/98ASA00090D.pdf
7.2
Recommended Footprint
Reference Freescale Application Note AN3111, latest revision:
http://www.freescale.com/files/sensors/doc/app_note/AN3111.pdf
Table 21. Revision History
Revision
number
Revision
date
9
03/2012
• Added SafeAssure logo, changed first paragraph and disclaimer to include trademark
information.
• Table 2: $04 DEVCFG1: Changed Bit Function 3 to 1.
• Section 3.1.2: Changed Bit 3 to 1 in register table.
• Section 3.1.2.1: Removed Axis column in table, changed last row g-cell design column to High-g.
10
07/2012
• Added Section 6: SPI Diagnostic and Programming Mode
11
08/2012
• Section 2.3: Lines 47 and 48 deleted.
• Section 2.6: Line 145, Time to program the OTP User Array Min value was 512 μs changed to
70 ms, changed symbol to tPROG_ARRAY.
• Section 2.8: Line 190, change Typ column from 6 / fOSC to 1.5, added Max column 5.0, changed
unit from “s” to “μs”.
• Section 2.7: Cutoff frequency, Option 1, Filter order, Option 1, Cutoff frequency, Option 2 and
Filter order, Option 2, table renumbering.
• Section 3.1: Changed “CRC circuitry” to “error detection circuitry”.
• Table 2: Changed bit names for address $0B from “CRC_U” to “UD”. Added $0D byte addr.
• Section 3.1.3.1: Changed “CRC Verification” to “Error Detection”.
• Section 3.1.5: Changed bit names for address $0B from “CRC_U” to “UD”.
• Section 3.1.5.4: Changed title from “User Configuration CRC (CRC_U[2:0])” to “User Specific
Data (UD[2:0])” and change contents of paragraph.
• Section 3.1.6.6 - Deleted.
• Section 3.1.6.2: Changed “CRC fault” to “error detection mismatch” in paragraph and Error
Condition column.
• Added Section 3.1.7 Manufacturer ID (MFG_ID).
• Section 3.2.2: Changed title from “User Programmable OTP Array CRC Verification” to User
Programmable OTP Array Error Detection” and updated paragraph contents.
• Table 6: Deleted 0.04 Hz HPF rows.
• Table 10: Updated F3 register address from “Hard-coded” to “MFG_ID[7:0]”; Description from
“Manufacturer = Freescale” to “Manufacturer ID”; Value from “0100 0110” to “User”.
• Section 5.4: Change step 4; deleted “a” and “b”, added step 5.
• Table 10: F7, D12 and D13 Value column from “0001” to “Factory”.
• Table 12: Added register name (MFG_ID) and bit function for Nibble IDs D4 H, D4 L, D5 H and
D5 L in Register Address column; changed Description column for all from “Satellite Manufacturer
= Freescale” to “Manufacturer ID”; changed Value column to “User”.
• Section 6.5.3: Changed first row from “DATASIZE = 0” to “DATASIZE = 1”, second row from
“DATASIZE = 1” to “DATASIZE = 0”.
• Section 6.6: Updated Steps 3-6. Deleted steps 7 and 8.
Description of changes
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© 2012 Freescale Semiconductor, Inc.
Document Number: MMA51xxKW
Rev. 11
08/2012