STMICROELECTRONICS L4969MD

L4969
SYSTEM VOLTAGE REGULATOR
WITH FAULT TOLERANT LOW SPEED CAN-TRANSCEIVER
PRELIMINARY DATA
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OPERATING SUPPLY VOLTAGE 6V TO 28V,
TRANSIENT UP TO 40V
LOW QUIESCENT CURRENT CONSUMPTION, LESS THAN 40µA IN SLEEP MODE
TWO VERY LOW DROP VOLTAGE
REGULATORS 5V / 200mA
AND 5V/200mA
SEPARATE VOLTAGE REGULATOR FOR
CAN-TRANSCEIVER SUPPLY WITH LOW
POWER SLEEP MODE
EFFICIENT UC SUPERVISION AND RESET
LOGIC
24 BIT SERIAL INTERFACE
AN UNPOWERED OR INSUFFICIENTLY
SUPPLIED NODE DOES NOT DISTURB THE
BUS LINES
VS VOLTAGE SENSE COMPARATOR
SUPPORTS TRANSMISSION WITH
GROUNDSHIFT:
SINGLE WIRE: 1.5V, DIFFERENTIAL: 3V
SO20
PowerSO20
ORDERING NUMBERS: L4969MD (SO20)
L4969 (PowerSO20)
DESCRIPTION
The L4969 is an integrated circuit containing 3 independent Voltage Regulators and a standard fault tolerant low speed CAN line interface in multipower
BCD3S process.
It integrates all main local functions for automotive body
electronic applications connected to a CAN bus.
Figure 1. Block Diagram
VS
V1
VREG 1
V2
VREG 2
V3
VREG 3
Watchdog and
adjustable RC-Oscillator
NRESET
Identifier Filter
WAKE
Control and Status Memory
RX
NINT
TX
CANH
RTH
CANL
RTL
Fault tolerant
low speed
CAN-transceiver
SCLK
24 Bit SPI
SIN
SOUT
August 2003
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
1/35
L4969
Figure 2. Pin Connection
GND
GND
SIN
V1
WAKE
SCLK
NRES
V2
NINT
NINT
TX
V3
NRES
WAKE
RX
VS
SCLK
GND
SIN
PSO20
SOUT
SO20
GND
GND
GND
SOUT
V1
RTH
CANL
TXD
V2
CANL
RTH
RXD
V3
RTL
GND
GND
VS
CANH
CANH
RTL
Table 1. Pin Functions
Pin No. (PSO20)
Pin No. (SO20)
Pin Name
1, 10, 11, 20
5,6, 15, 16
GND
Function
2
7
V1
Microcontroller Supply Voltage
3
8
V2
Peripheral Supply Voltage
Power Ground
4
9
V3
Internal CAN Supply
5
10
VS
Power Supply
6
11
CANH
CANH Line Driver Output
7
12
RTL
CANL Termination Source
8
13
CANL
CANL Line Driver Output
9
14
RTH
CANH Termination Source
12
17
RXD
Act. Low CAN Receive Dominant Data Output
13
18
TXD
14
19
SOUT
15
20
SIN
16
1
SCLK
Serial Clock
17
2
NRES
Act. Low Reset Output
18
3
NINT
Act. Low Interrupt Request
19
4
WAKE
Act. Low CAN Transmit Dominant Data Input
Serial Data Output
Serial Data Input
Dual Edge Triggerable Wakeup Input
Table 2. Thermal Data
Symbol
Parameter
Rthj-amb
Thermal resistance junction-ambient
Rthj-case
Thermal resistance junction-case
Note: 1. Typical value soldered on a PC board with 8 cm2 copper ground plane (35 µm thick).
2/35
Value
Unit
401)
°C/W
3
°C/W
L4969
Table 3. Absolute Maximum Ratings
Symbol
Parameter
VVSDC
DC operating supply voltage
VVSTR
Transient operating supply voltage (T < 400ms)
IVOUT1...3
TSTG
TJ
Value
Unit
-0.3 ... +28
VVSDC
-0.3 ... +40
VVSTR
Internally limited
IVOUT1...3
Storage temperature
-65 ... +150
TSTG
Operating junction temperature
-40 ... +150
TJ
-0.3 ... VS+0.3, max +6.3
VOUT1
Output currents
VOUT1
Externally forced output voltage OUT1
VOUT2
Externally forced output voltage OUT2
-0.3 ... VS+0.3
VOUT2
VOUT3
Externally forced output voltage OUT3
-0.3 ... VS+0.3, max +6.3
VOUT3
-0.3 ... +7
Vinli
Vinli
Input voltage Logic inputs: SIN, SCLK, NRES
VinliW
Input voltage WAKE
-0.3 ... VS+0.3
VinliW
Vcanh
Voltage CANH line
3
-28 ... +40
Vcanh
Vcanl
Voltage CANL line 3
-28 ... +40
Vcanl
Notes: 1. All pins of the IC are protected against ESD. The verification is performed according to MIL 883C,
human body model with R = 1.5kW, C = 100pF and discharge voltage 2000V,
corresponding to a maximum discharge energy of 0.2mJ..
2. Voltage forced means voltage limited to the specified values while the current is not limited.
3. ESD Pulses on CAN-Pins up to 4KV HBM vs GND with all other Pins grounded.
Table 4. Electrical Characteristics
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
Supply Current
ISSL
ISSLWK
ISSB
IS
ISCP
All Regulators off
(CANH Standby
Timer off (Sleep #1)
30
40
60
µA
Timer on (Sleep #2)
70
90
135
µA
4
6
mA
150
250
µA
V1 off, V2 off, V3 on
(CAN RX only)
RXonly
V1 only (CAN Standby)
Timer off (Standby #1)
Timer on (Standby #2)
200
300
µA
Default (Standby #3)
440
600
µA
All Regulators on,
(CAN active, TX high)
IOUT1 = -100mA
IOUT2 = -10mA
No CAN load.
120
150
mA
Additional Oscillator- and
Chargepumpcurrent at low VS
VS = 6V; Timer Off
55
80
100
µA
VS = 6V; Timer On
10
30
50
µA
6V < VS < 28V
IO >-100mA
SO20 Package
4.9
5
5.1
V
6V < VS < 28V
IO >-150mA
PSO20 Package
4.9
5
5.1
V
IOUT1 = -10mA
0.0
0.025
0.06
V
IOUT1 = -100mA
SO20 Package
0.0
0.25
0.6
V
IOUT1 = -150mA
PSO20 Package
0.0
0.4
0.9
V
Voltage Regulator 1
V01
VDP1
V1 output voltage
Dropout voltage 1@ VS=4.8V
3/35
L4969
Table 4. Electrical Characteristics (continued)
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
VOL01
ILIM1
Parameter
Load regulation 1
Current limit 1
Min.
Typ.
Max.
Unit
IO =-1mA to-100mA
SO20 Package
Test Conditions
0
10
40
mV
IO =-1mA to -150mA
PSO20 Package
0
10
40
mV
0.8V < VO1 < 4.5V, VS=6V,
SO20 Package
-180
-400
-800
mA
0.8V < VO1 < 4.5V
VS=14V,
PSO20 Package
-180
-400
-800
mA
VOLI1
Line regulation 1
6V < VS < 28V
IO1 = -1mA
0
5
30
mV
TOVT1
Overtemp flag 1
6V < VS < 28V
130
140
150
°C
TOTKL1
Thermal shutdown 1
6V < VS < 28V
Vres
175
185
205
°C
Min V1 reset threshold voltage RTC0 = 0
4.15
4.5
4.7
V
RTC0 = 1
3.7
4.0
4.2
V
6V < VS < 28V
IO >-100mA
SO20 Package
4.8
5
5.2
V
6V < VS < 28V
IO >-150mA
PSO20 Package
4.8
5
5.2
V
VS = 4.8V
IO UT = 100mA
SO20 Package
0.0
0.25
0.6
V
IO UT = 150mA
PSO20 Package
0.0
0.4
0.9
V
IO =-1mA to -100mA
SO20 Package
0
10
40
mV
IO =-1mA to -150mA
PSO20 Package
0
10
40
mV
0.8V < VO1 < 4.5V, VS=6V,
SO20 Package
-180
-400
-800
mA
0.8V < VO1 < 4.5V
PSO20 Package
-180
-400
-800
mA
Voltage Regulator 2 and 3
VO
VDP
VOLO
ILIM
Output voltage
Dropout voltage
Load regulation
Current limit
VOLI
Line regulation
6V < VS < 28V
IOUT = -5mA
0
5
30
mV
TOVT
Overtemp flag
6V < VS < 28V
130
140
150
°C
TOTKL
Thermal shutdown
150
165
180
°C
Vtrc
V2 tracking offset
6V < VS < 28V
6V < VS < 28V, IO2 = 0
-90
0
+90
mV
RC-Adjustment = 0
0.95
1.1
1.35
Reset and Watchdog
tOSC
OnChip RC-Timebase
tWDC
Watchdog timebase (2.5ms)
2498
tOSC
tRDnom
Reset pulse duration (1ms)
1024
tOSC
tWDstart
Reset pulse pause (320ms)
(startup watchdog)
128
tWDC
4/35
us
L4969
Table 4. Electrical Characteristics (continued)
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
Parameter
tWDswS
Watchdog window start
(Software window Watchdog)
tWDswE
tWD1C
tWD2C
Watchdog window end
(Software window watchdog)
System Watchdog 1
System Watchdog 2
Test Conditions
Min.
tWDC
2
tWDC
SWT = 2 (10ms)
4
tWDC
SWT = 3 (20ms)
8
tWDC
SWT = 0 (5ms)
2
tWDC
SWT = 1 (10ms)
4
tWDC
SWT = 2 (20ms)
8
tWDC
SWT = 3 (40ms)
16
tWDC
WDT = 0 (80ms)
32
tWDC
WDT = 1 (160ms)
64
tWDC
WDT = 2 (320ms)
128
tWDC
WDT = 3 (640ms)
256
tWDC
WDT = 4 (800ms)
320
tWDC
WDT = 8 (1s)
400
tWDC
WDT = 9 (2s)
784
tWDC
WDT = 10 (4s)
1600
tWDC
IRES = 500u, V1 = 2.5V
IRES = 500u, V1 = 1.5V
RPURES
Unit
SWT = 1 (5ms)
WDT = 12 (45min)
Reset output LOW voltage
Max.
1
WDT = 11 (8s)
VRESL
Typ.
SWT = 0 (2.5ms)
Internal Reset Pull-Up
Resistance
3200
tWDC
1081344
tWDC
0
0.3
0.4
V
0
0.85
1.4
V
80
120
280
KΩ
CAN Line Interface
tdrd
Propagation delay
(rec to dom state)
Cload = 3.3n
0.4
1.0
1.5
µs
tddr
Propagation delay
(dom to rez state)
Cload = 3.3n,
RTERM =100
0.4
1.0
2.0
µs
SRD
Bus output slew rate (r -> d)
10% ... 90%
CLoad = 3.3n
4
5
8
V/µs
0.5
16
KΩ
2.20
4.0
V
RRTH, RRTL external Termination
resistance
(application limit)
VCCFS
Force Standby mode (fail
safe)
min VS to turn off CAN-IF and
V3
VHRXD
High level output voltage on
RXD
V1 - 0.9
V1
V
VLRXD
Low level output voltage on
RXD
0
0.9
V
Vd_r
Differential receiver
dom to rec threshold
VCANH - VCANL
No bus failures
-3.85
-2.50
V
Vr_d
Differential receiver
rez to dom threshold
VCANH - VCANL
No bus failures
-3.50
-2.20
V
5/35
L4969
Table 4. Electrical Characteristics (continued)
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
0.35
V
VCANHr
CANH recessive output
voltage
TXD = V1
RRTH < 4K
VCANHd
CANH dominant output
voltage
TXD = 0
ICANH = 40mA
V3 1.4V
V
VCANLr
CANL recessive output
voltage
TXD = V1
RRTL < 4K
V3 0.2V
V
VCANLd
CANL dominant output
voltage
TXD = 0
ICANL = -40mA
ICANH
CANH dominant output
current
TXD = 0
VCANH = 0V
70
ICANL
CANL dominant output
current
TXD = 0
VCANL = 14V
-70
ILCANH
CANH Sleep mode
leakage current
Sleep mode. Tj=150°C
VCANH = 0V
0
µA
ILCANL
CANL Sleep mode
leakage current
Sleep mode. Tj=150°C
VCANL = 0V
VS = 12V
0
µA
VWakeH
CANH wakeup voltage
Sleep/
standby mode
1.2
1.9
2.7
V
VWakeL
CANL wakeup voltage
Sleep/
standby mode
2.4
3.1
3.8
V
Vcanhs
CANH single ended
receiver threshold
Normal mode.
-5V < CANL < VS
1.5
1.82
2.15
V
Vcanls
CANL single ended
receiver threshold
Normal mode.
-5V < CANH< VS
2.7
3.1
3.4
V
VOVH
CANH overvoltage
detection threshold
Normal mode.
-5V < CANL < VS
6.5
7.2
8.0
V
VOVL
CANL overvoltage
detection threshold
Normal mode.
-5V < CANH < VS
6.5
7.2
8.0
V
RTRTH
internal RTH to GND
termination resistance
Normal mode, No failures.
VRTH = 1V
30
45
80
W
ITRTHF
internal RTH to GND
termination current
Normal mode, Failure EIII
VRTH =V3 - 1V
55
75
100
µA
RTRTL
internal RTL to VCC
termination resistance
Normal mode, no failures.
VRT L =V3 - 1V
30
45
85
W
ITRTLF
internal RTL to VCC
termination current
Normal mode.
(failure EIV, EVI, EVII)
VRTL =V3 - 1V
-6
-40
-70
µA
RTRTLS
internal RTL to VS
termination resistance
No failures.
Standby/sleep mode.
VRTL =1V, 4V
8
13.0
26
KΩ
0.9
V
1.4
V
100
160
mA
-100
-160
mA
Digital I/O
VSINL
Low level input voltage
0
VSINH
High level input voltage
V1 - 0.9
V1
V
VSCLKL
Low level input voltage
0
0.9
V
6/35
L4969
Table 4. Electrical Characteristics (continued)
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
VSCLKH
High level input voltage
V1 - 0.9
V1
V
VTXL
Low level input voltage
0
0.9
V
VTXH
High level input voltage
V1 - 0.9
V1
V
VWakeL
Low level input voltage
0
0.9
V
VWakeH
High level input voltage
4.1
5.0
V
VSoutH
High level output voltage
V1 - 0.9
V1
V
VSoutL
Low level output voltage
0
0.9
V
VRXDH
High level output voltage
V1 - 0.9
V1
V
VRXDL
Low level output voltage
0
0.9
V
IohRXD
High level output current
RXD = 0
-1.2
-1.8
-2.5
mA
IolRXD
Low level output current
RXD = 5V
1.1
1.6
2.2
mA
IohSOUT
High level output current
SOUT = 0
-9.0
-14.0
-18.0
mA
IolSOUT
Low level output current
SOUT = 5V
18.0
24,0
30.0
mA
IohINT
High level output current
INT = 0
-10.0
-15.0
-20.0
mA
IolINT
Low level output current
INT = 5V
18,0
24,0
30,0
mA
IohReset
High level output current
RESET = 0
-6,0
-15,0
-25.0
µA
IolReset
Low level output current
RESET = 5V
5.0
6.5
8.0
mA
IohWake
High level output current
VWake = 5V
0
0
0.5
µA
IolWake
Low level output current
VWake = 0V
-2.2
-3.4
-4.5
µA
Serial Data Interface
tStart
SIN low to SCLK low setup
time
(frame start)
100
ns
tSetup
SIN to SCLK setup time
(write)
100
ns
tHold
SIN to SCLK hold time
(write)
100
ns
tD
SCLK to SOUT delay time
(read)
tCKmax
SCLK maximum cycle time
(timeout)
tGAP
Interframe Gap
fSCLK
SCLK frequency range
500
ns
1.5
3.0
ms
0.25
0.5
1
MHz
1
µs
5
Diagnostic Functions
VSmin
Sense comparator
detection threshold
6.0
7.2
8.0
V
GSCANH
CANH groundshift
detection threshold
-1.5
-1
-0.6
V
CAN Error Detection
NEdgeH
Nr of dom to rec edges on
CANL to detect permanent
rez CANH
Operating mode (EI_V)
3
Edges
NEdgeHR
Nr of dom to rec edges to
detect
recovery of CANH
Operating mode (EI_V)
3
Edges
7/35
L4969
Table 4. Electrical Characteristics (continued)
VS = 14V, Tj = -40°C to 150°C unless otherwise specified.
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
NEdgeL
Nr of dom to rec edges on
CANH to detect permanent
rez CANL
Operating mode (EII_IX)
3
Edges
NEdgeLR
Nr of dom to rec edges to
detect
recovery of CANL
Operating mode (EII_IX)
3
Edges
tEIII
CANH to VS short circuit
detection time
Operating mode (EIII)
1.6
2
3.6
ms
Sleep/
standby mode (EIII)
1.6
2
3.6
ms
tEIIIR
tEIV
tEIVR
CANH to VS short circuit
recovery time
CANL to GND short circuit
detection time
CANL to GND short circuit
recovery time
Operating mode (EIII)
0.4
0.9
1.6
ms
Sleep/
standby mode (EIII)
0.4
0.9
1.6
ms
Operating mode (EIV)
0.4
0.9
1.6
ms
Sleep/
standby mode (EIV)
0.4
0.9
1.6
ms
Operating mode (EIV)
10
30
50
µs
Sleep/
standby mode (EIV)
0.4
0.9
1.6
ms
tEVI
CANL to VS short circuit
detection time
Operating mode (EVI)
0.4
0.9
1.6
ms
tEVIR
CANL to VS short circuit
recovery time
Operating mode (EVI)
200
500
750
µs
tEVII
CANL to CANH short circuit
detection time
Operating mode (EVII)
0.4
0.9
1.6
ms
tEVIIR
CANL to CANH short circuit
recovery time
Operating mode (EVII)
10
30
50
µs
tEVIII
CANH to VDD short circuit
detection time
Operating mode (EVIII)
1.6
1.8
3.6
ms
Sleep/
standby mode (EVIII)
1.6
1.8
3.6
ms
CANH to VDD short circuit
recovery time
Operating mode (EVIII)
0.4
0.9
1.6
ms
Sleep/
standby mode (EVIII)
0.4
0.9
1.6
ms
tFailTX
TX permanent dominant
detection time (Fail safe)
Operating mode (EX)
0.4
0.9
1.6
ms
tFailTXR
TX permanent dominant
recovery time (Fail safe)
Operating mode (EX)
1
4
8
µs
twuCAN
Minimum dominant time for
wake-up via CANH or CANL
sleep/standby
8
22
38
µs
twuWK
Minimum pulse time for wakeup via WAKE
sleep/standby
8
22
38
µs
tEVIIIR
Wakeup
8/35
L4969
1
FUNCTIONAL DESCRIPTION
1.1 General Features
The L4969 is a monolithic integrated circuit which provides all main functions for an automotive body
CAN network.
It features two independent regulated voltage supplies V1 and V2, an interrupt and reset logic with internal clock
generator, Serial Interface and a low speed CAN-bus transceiver which is supplied by a separate third voltage
regulator (V3).
The device guarantees a clearly defined behavior in case of failure, to avoid permanent CAN bus errors.
The device operates in four basic modes, with additional programming for V1 Standbymodes in CTCR:
Mode
V1
V2
V3
Timer/WDC
CAN-IF
Ityp
LP1, LP0
(CTCR)
Remarks
Sleep #1
Off Off Off
Off
Standby
40u
x,x
No Timer based wakeup
Sleep #2
Off Off Off
On (250KHz)
Standby
80u
x,x
Timer active
Standby #1(*1) On Off Off
Off
Standby
170u
1,1
No Watchdog or Timer
Standby #2(*1) On Off Off
On (250KHz)
Standby
210u
1,0
Watchdog or timer active
Standby #3
On Off Off
On (1MHz)
Standby
440u
0,0
Watchdog or timer activ, POR default
RXOnly
Off Off On
On (1MHz)
RX-Only
4mA
x,x
Active during Busactivity to filter ID, automatic fall back to Sleep when Bus idle
Normal
On On On
On (1MHz)
Normal
5mA
x,x
No Currents from CAN or Regulators
(*1) Note, that in order to enter either Standby #1 or Standby #2 the Startup-Watchdog has to be acknowledged (see Chapter 1.2), in Standby
#1, the Window Watchdog has to be disabled as described in Chapter 2.5, to allow the decativation of the internal oscillator.
1.1.1 V1 Output Voltage
The V1 regulator uses a DMOS transistor as an output stage. With this structure very low dropout voltage is
obtained. The dropout operation of the standby regulator is maintained down to 4V input supply voltage. The
output voltage is regulated up to the transient input supply voltage of 40V. With this feature no functional interruption due to overvoltage pulses is generated. The output 1 regulator is switched off in sleep mode.
1.1.2 V2 Output Voltage
The V2 regulator uses the same output structure as the output 1 regulator except to being short circuit proof to
VS, and to be rated for the output current of 200mA. The V2 output can be switched on and off through a dedicated enable bit in the control register. In addition a tracking option can be enabled to allow V2 follow V1 with
constant offset. This feature allows consistent A/D conversion inside the µC (supplied by V1) when the converted signals are referenced to V2. The maximum voltage that can be applied to V2 is VS + 0.3V up to a max VS
of 40V.
1.1.3 V3 Output Voltage
The third voltage regulator of the device generates the supply voltage for the internal logic and the CAN-transceiver. In operating mode it is capable of supplying up to 200mA in order to guarantee the required short circuit
current for the CAN_H driver. The sleep and operating modes are switched through a dedicated enable bit.
1.1.4 Internal Supply Voltage
A low power sleep mode regulator supplies the internal logic in sleep mode.
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L4969
1.2 Power-Up, Initialization and Sleep mode transitions
The following state-diagram illustrates the possible mode transitions inside the device.
As a prerequisite, a SPI-connection to the uC with the correct CRC-algorythms is required.
During the debug phase the NRES line can be forced high externally (connect to V1) to deactivate the startup
failure mechanis keeping V1 will alive.
Figure 3.
The forced sleep mode is left upon wakeup through either CAN or edge on
WAKE. Applying a permanent wakeup (i.e. both CAN-lines dominant) prevents V1 from being turned off (can be used during System debugging)
After POR, V1 up or externally forced reset
through low NRES, the STARTUP STATE is
entered
WAKEUP
V1 Low
Forcing NRES high externally, fail will not be incremented (Emulation)
NRES Low
STARTUP
V1 active
V2, V3, CAN off
WAKEUP
t=320ms
t=1ms
STARTUP
FAILURE
RESET low
WDC-FAIL
Writing to the WDCregister
(WDC-ACK)
the NORMAL STATE is
entered.
Dependig on the value from the last
WDC-ACK, another one has to be
written within the specified time frame
(SWDC[1:0]). A failure will activate
the STARTUP STATE
NORMAL MODE WDC-ACK
WINDOW WDC t=tWIN2
WDC-OK
ACTIVE
DISABLED
WAKEUP
WINDOW
WATCHDOG
REFRESH
WDEN SET
TIMER
ACTIVE
(restart by double
WDC-ACK & WDEN)
WDEN SET
TIMEOUT | WDC-ACK
Here the timer can be used to
generate time events (i.e.
wakeup uC from stop)
TIMER
ACTIVE
(restart by double
WDC-ACK & WDEN)
DISAR
SET
Programmed
SLEEP
V1 OFF
No Reset
WAKEUP&V1_UV
10/35
The Window supervision can temporarily be deactivated for the time programmed during the
last WDC-ACK (WDT[3:0]). Upon rewriting
(WDC-ACK) or expiry of the timer, the NORMAL
STATE is reentered.
If during the last WDC-ACK WND has been set (after releasing
write lock, see description of Watchdog Control Register) the Window watchdog is deactivated, and no uC supervision is active.
NORMAL MODE
WINDOW WDC
WAKEUP
&V1_UV
WDC-ACK
&
WDEN SET
If no WDC-ACK is received within
seven retrials the voltage regulator
V1 will be turned off by entering the
FORCED SLEEP state.
TIMEOUT | WDC-ACK
WND SET
DISAR
SET
FORCED SLEEP
V1 off
No Reset
(fail ++)
A missing ACK within 320ms will
initiate a STARTUP FAILURE
phase (RESET low).
WDC-ACK
fail = 7
Setting DISAR (see Voltage Regulator Control Register) Voltage regulator V1 is
turned off, and the output voltage is decreasing depending on the external load
and blocking capacitor.
Note, that during this transition no Reset will be generated (due to Debugmode).
Upon wakeup howewer NRES will be pulled low, if V1was below the programmable reset threshold (V1_UV).
L4969
1.3
CAN Transceiver
– Supports double wire unshielded busses
– Baud rate up to 125KBaud
– Short circuit protection (battery, ground, wires shorted)
– Single wire operation possible (automatic switching to single wire upon bus failures)
– Bus not loaded in case of unpowered transceiver
The CAN transceiver stage is able to transfer serial data on two independent communication wires either deferentially (normal operation) or in case of a single wire fault on the remaining line. The physical bitcoding is done
using dominant (transmitter active) and overwritable recessive states. Too long dominant phases are detected
internally and further transmission is automatically disabled (malfunction of protocol unit does not affect communication on the bus, "fail-safe" - mechanism). For low current consumption during bus inactivity a sleep mode
is available. The operating mode can be entered from the sleep mode either by local wake up (µC) or upon detection of a dominant bit on the CAN-bus (external wake up).
Ten different errors on the physical buslines can be distinguished:
1.3.1 Detectable Physical Busline Failures
N
Type of Errors
Conditions
Errors caused by damage of the datalines or isolation
I
CANH wire interrupted (tied to Ground or termination)
Edgecount difference > 3
II
CANL wire interrupted (floating or tied termination)
Edgecount difference > 3
III
CANH short circuit to VBAT (overvoltage condition)
V(CANH) > 7.2V after 32us
IV
CANL short circuit to GND (permanently dominant)
V(CANL) < 3.1V & V(CANH)-V(CANL)
< -3.25V after 1.3ms
V
CANH short circuit to GND (permanently recessive)
Edgecount difference > 3
VI
CANL short circuit to VBAT (overvoltage condition)
V(CANL) > 7.2V after 32us
VII
CANL shorted to CANH
V(CANH) - V(CANL) < -3.25V after
1.3ms
Errors caused by misbehavior of transceiver stage
VIII
CANH short circuit to VDD (permanently dominant)
V(CANH) > 1.8V & V(CANH) V(CANL) < -3.25V after 2.5ms
IX
CANL short circuit to VDD (permanently recessive)
Edgecount difference > 3
Errors caused by defective protocol unit
X
CANH, CANL driven dominant for more than 1.3ms
Not all of the 10 different errors lead to a breakdown of the whole communication.
So the errors can be categorized into 'negligible', 'problematic' and 'severe':
11/35
L4969
1.3.2 Negligible Errors
1.3.2.1 Transmitter
Error I and II (CANH or CANL interrupted but still tied to termination)
Error IV and VIII (CANH or CANL permanently dominant by short circuit)
In all cases above data can still be transmitted in differential mode.
1.3.2.2 Receiver
Error I and II (CANH or CANL interrupted but still tied to termination)
Error V and IX (CANH or CANL permanently recessive by short circuit)
In all cases above data can still be received in differential mode.
1.3.3
Problematic Errors
1.3.3.1 Transmitter
Error III and VI (CANH or CANL show overvoltage condition by short circuit)
Data is transmitted using the remaining dataline (single wire)
1.3.3.2 Receiver
Error III and VI (CANH or CANL show overvoltage condition by short circuit)
Data is received using the remaining dataline (single wire)
1.3.4 Severe Errors
1.3.4.1 Transmitter
Error V and IX (CANH or CANL permanently recessive by short circuit)
Data is transmitted on the remaining dataline after short circuit detection
Error VII (CANH is shorted to CANL)
Data is transmitted on CANH or CANL after overcurrent was detected
Error X (attempt to transmit more than 10 successive dominant bits (at lowest bitrate specified)
Transmission is terminated (fail safe)
1.3.4.2 Receiver
Error VII (CANH is shorted to CANL)
Data is received on CANH or CANL after detection of permanent dominant state
Error IV and VIII (CANH or CANL permanently dominant by short circuit)
Data is received on CANH or CANL after short circuit was detected
Error X (reception of a sequence of dominant bits, violating the protocol rules)
Data is received normally, error is detected by protocol-unit
The error conditions is signaled issuing an error flag inside a dedicated register which is readable by the µC
through the serial interface. The information of the error type (I through X) is also stored into this register.
12/35
L4969
1.4 Oscillator
A low power oscillator provides an internal clock. In sleep mode (Watchdog active) the output frequency is
250kHz, if the Watchdog function is not requested, the internal Oscillator is switched off.
In standby and operating mode the oscillator is running at 1MHz, and can be calibrated in a range from -16% to
+16% using the µC-XTAL as a reference.
1.5 WatchdL4969og
A triple function programmable watchdog is integrated to perform the following tasks:
– Wakeup Watchdog:
When in sleep or standby mode the watchdog can generate a wakeup condition after a programmable period of time ranging from 80ms up to 45 minutes
– Startup Watchdog:
Upon V1 power-up or µC failure during SPI supervision (see SW-Watchdog) a reset pulse is generated periodically every 320ms for 2.5ms until activity of the µC is detected (SPI sequence) or no acknowledge is received within 7 cycles (2.2sec). In this condition the device is forced into Sleep mode
until a Wakeup is detected and a startup cycle is reinitialized.
– Window Watchdog:
After passing the startup sequence, this watchdog request an acknowledge by the µC via the SPI
within a programmable timing frame, ranging from 2.5 ... 5ms up to 20 ... 40ms. Upon a missing or
misplaced acknowledge the Startup Watchdog is initialized.
1.6
Reset
1.6.1 Power-on Reset
Upon Power-on (VS > 3.5V), the internal reset forces the device into a predefined power-on state (see 1.1):
Standby #3:V1 on V2 off V3 off,CAN-Standby mode, ID-Filter disabled, Startup Watchdog active
With VS below 5V the regulator V1 will follow VS with minimum drop. The µC retrieves a reset if V1 is dropping
below a programmable voltage level of either 4.5V (default) or 4.0V. The programmed state of the L4969 remains unchanged. The act. low Resetpulse duration is fixed internally by an open-drain output stage to 1ms.
However, this time can be externally extended by an additional capacitance connect between NRESET and
GROUND which is then charged by the internal pull-up of typ. 120K. Depending on the Reset-Input-Threshold
of the uC (UTR), the reqired Capacitance for a typical tD can be calculated as follows:
CEXT = -tD / (120E3 ln(1-UTR/V1))).
To obtain a reset-pulse duration of tD = 50ms with UTR/V1 = 0.5, a Capacitance of CEXT= -50E-3 / (120E3 ln
0.5) = 600nF is required.
Figure 4.
V1
120K
to Reset Input of uC
NRES
CEXT
1.6.2 Undervoltage Reset
Upon detection of a V1 voltage level below a programmable voltage level of either 4.5V (default) or 4.0V,the
NRES-pin is pulled low. Since this undervoltage detection is additionally sampled periodically every ms, the
NRES low time will be extended by up to 1 ms if V1 was low (V1 UV) at the sampling point (see below).
13/35
L4969
Figure 5.
1ms sampling
V1UV
NRES
1.6.3 Reset signalling during Sleepmode
When entering the sleep mode by writing 1 to DISAR in the VRCR register, the Voltageregulators and their references will be deactivated to allow minimum current consumption. By removing the V1 reference, the outputvoltage is no longer supervised and thus NO reset will be generated.
Now two scenarios are possible (see statediagram in chapter 1.2):
1) Wakeup with V1 still above reset threshold: V1 will be reactivated and Normal mode is resumed
2) Wakeup with V1 below reset threshold: V1 will be activated, NRES will go low and remain low until V1 is
above reset threshold and Startup mode is entered.
The scenario 2 is the most critical when used with uC that do not have their own POR circuitry.
In this case V1 will ramp down with an unknown application state.
To guarantee a proper shut off of an uC without an internal POR circuitry the following mechanism can be utilized: The L4969 uses a bidirectional Reset to detect a possible Watchdog failure of the uC. If this failure condition is detected, NRES will be forced low for 1 ms (with activated timer) or until a wakeup condition occurs
(WDEN bit in WDC register reset, thus RC-oscillator will be switched off during sleep).
Two methods can be used to allow a proper sleep transition:
- With Timer (WDEN=1): immediately after setting DISAR the uC has to program its WDC to generate a failure
causing the L4969 to detect a low level on NRES followed by an automatic 1ms pulse extension. If V1 is ramping
down slow, Cext has to be defined in a way, that NRES will stay below the input threshold of the uC until V1 is
in a safe level.
- Without timer (WDEN=0): same procedure as above, but uC has to generate a Reset within 1 ms after WDEN
has been cleared. NRES will then stay low, until a wakeup condition occurs.
Figure 6. .
DISAR
V1
REF REG
R1
R2
NRES
WDC
1ms
CEXT
RC-Osc
uC
L4969
1.7 Identifier Filter
A 12-Bit CAN-ID-filter is implemented allowing wakeup via specific CAN-messages thus aiding the implementation of low power partial communication networks like standby diagnostics without the need to power-up the
whole network.
To guarantee the detection of the programmed Identifiers, the local RC-oscillator can be calibrated to allow the
programmable Bittime logic to extract the incoming stream with a maximum of tolerance over temperature deviation.
1.8
14/35
Ground Shift Detection
L4969
In case of single wire communication via CANH the signal to noise ratio is low. Detecting the local ground shift
can be used as an additional indicator on the current signal quality. The information of the integrated ground
shift detector will be refreshed upon every falling edge on TX and can be read from the CAN Transceiver Status
Register (CTSR).
It will be set, if V(CANH) < -1V, reset if V(CANH > -1V) at the falling edge of TX.
1.9 Thermal Protection
The device features three independent thermal warning circuits which monitor the temperature of the V1 output,
the V2 output and the CAN_H and CAN_L drivers together with voltage regulator V3. Each circuit sets a separate overtemperature flag in a register which is read and writable by the serial interface. The overtemperature
flags cause an interrupt to the µC. The µC is able to switch V1, V2 and CAN drivers on and off through dedicated
enable registers. To enhance system security following strategy is chosen for thermal warning and shutdown:
– 3 independent warning flags are set at 140°C for V1, V2 and V3 /CAN-Transceiver
– at 170°C V2 and V3 switched off
– at 200°C V1 is switched off
– V2 and V3 can be switched on again through the µC
– V1 can be switched on again at wake-up (Watchdog wake-up, CAN wake-up, external wake-up)
Note, that if no wakeup source is set for V1 a 1sec watchdog timeout will be established to enable a proper retry
cycle.
1.10 Serial Interface (SPI)
A standard serial peripheral interface (SPI) is implemented to allow access to the internal registers of the L4969.
A total of 12 Registers with different datalengths can be directly read from or written to, providing the requested
address at the beginning of a dataframe. Upon every access to this interface, the content of the register currently
accessed is shifted out via SOUT. All operations are performed on the rising edge of SCLK.
If a frame is not completed, the interface is automatically reset after 1.5ms of SCLK idle time (auto timeout detection). If a message is corrupted (additional or missing SCLK pulses), the application software can detect this
by evaluating the returned value of the crc and force a communication gap of min 1.5ms to allow communicvation recovery. A corruption can be caused during startup of the uC and SPI initialization. The application should
then wait at least 1.5ms after SPI init prior to starting the communication.
The dataframe format used described on the next page:
15/35
L4969
1.10.1General Dataframe Format:
Figure 7.
SIN
ADR/CMD
7
Datafield 1 (W/R)
0
SOUT
15
ADR/CMD
7
Datafield 2/CRC (W/R)
8
23
Datafield 1 (R)
0
Datafield 2/CRC (R)
8
15
15
23
15
SCLK
99AT0015
Data is sampled on the rising edge of the clock and SOUT will change upon SCLK falling. SOUT will show a
copy of SIN for the Address/Command field for initial data path checks. Independent of the command state,
SOUT will show the content of the register addressed. SIN contains either data to be written or arbitrary data
for all other operations. The transaction will be terminated with four bit of data followed by a 4-Bit wide CRC
(Cyclic Redundancy Check) as a result of either SIN related data or calculated automatically on data returned
via SOUT. Here the µC has to provide the correct sequence in order to get the write command activated inside.
A CRC-failure is signalled via NINT. For returned data the CRC can also be used to verify a successful transfer.
1.10.2 Address/Command Field
Figure 8.
7
0
0
1
ADR3
Frame start sequence
always has to be
transmitted as 0 1
ADR2
ADR1
ADR0
Addressfield specifying
the Control/Status word
to be accessed
C1
C0
SPI command:
00: Read register
01: Clear IFR
10: illegal command
11: Write register
The Address/Command field starts with a 2-Bit start sequence consisting of ‘01’. Any other sequence will lead
to a protocol error signalled via the NINT. The addressfield is specifying the register to be accessed. The SPI
command flags allow in addition to the normal read/write operation to clear the Interrupt flag register after read.
16/35
L4969
1.10.3 Datafield #1
Figure 9.
D7
D6
D5
D4
D2
D3
D1
D0
Lower 8 Bit of 12 Bit data
SIN: Data to write
SOUT: Data currently in selected register
99AT0017
Datafield #1 contains either the lower 8 bits of a 12-Bit frame or the complete byte of an 8-Bit transfer.
Note, that SOUT is always showing the content of the register currently accessed and not a copy of SIN as during the Address/ Command field.
1.10.4 Datafield #2 /CRC
Figure 10.
D11
D10
D9
D8
CRC3
Upper 4 Bit of 12 Bit data (Zero if 8 Bit data)
SIN: Data to write
SOUT: Data currently in selected register
CRC2
CRC1
CRC0
CRC Check sequence
to be appended to tranferred data
Note that upon CRC check failure
no write operation will be performed
SIN: CRC of SIN sequence
SOUT: CRC of SOUT sequence
99AT0018
Datafield #2 contains either the upper four bits of a 12-Bit frame or zeros in case of an 8-Bit transfer. This field
is followed by a four bit CRC sequence that is calculated based upon the polynom 0x11h (17 decimal). This
sequence is simply the remainder of a polynomial division performed on the data previously transferred. If the
CRC appended to the SIN sequence fails, any writing will be disabled and an error is signalled via NINT. Another
remainder is calculated on the SOUT stream and appended accordingly to allow the application software to validate the correctness of incoming data. To aid evaluation, the CRC checking can be turned off by writing arbitrary data with a valid CRC to address 15. CRC-checking will be reenabled upon another operation of this kind
(Toggled information).
17/35
L4969
1.11 Memory Map
Table 5.
L4969 Memory Map
ADR
Group
MSB
D10
D9
D8
0
VRCR
1
CTCR
2
GPTR
3
RCADJ
4
WDC
5
GIEN
6
IFR
ESPI
ISET
IRES
UV23
7
CTSR
RES
RES
RES
8
ID01
A11
A10
A01
9
ID23
D11
D10
10
BTL
PS23
PS22
11
NAV
12
NAV
13
NAV
14
TEST
T11
15
SYS
Undefined Register Memory
Undefined
Register Memory
D7
D6
D5
D4
D3
D2
D1
D0
EUV3
EUV2
RTC0
TRC
RES
ENV3
ENV2
DISAR
ACT
TXEN
RES
RES
RES
LP2
LP1
LP0
RES
RES
RES
RES
TM1
TM0
TMUX
TEN
CG1
CG0
PGEN
SIGN
ADJ3
ADJ2
ADJ1
ADJ0
WDEN
WND
SWT1
SWT0
WDT3 WDT2
WDT1
WDT0
ISET
IRES
EUV
EOVT
EEW
ECW
EWW
EIFW
UVVS
OVT3
OVT2
OVT1
WKE
WKC
WKW
WKIF
GSH
EX
EVIII
EVII
EVI
EIV
EIII
EII
EI
A00
B11
B10
B01
B00
C11
C10
C01
C00
D01
D00
E11
E10
E01
E00
F11
F10
F01
F00
PS21
PS20
PS13
PS12
PS11
PS10
TD3
TD2
TD1
TD0
Undefined
Register Memory
T10
T09
T08
T07
T06
T05
T04
T03
T02
T01
T00
NCRC
STAT
WNDF
STF
OTF
UCF
WAKE
NPOR
The memory space is divided up into 16 different registers each being directly accessible using the SPI.
Each register contains specific information of a functional group.
In general al reserved bitpositions (‘RES’) have to be written with ‘0’.
Undefined bits are read as ‘0’ and cannot be overwritten.
In addition there is one register (CTSR) being read only, thus any write attempt will leave the register content
unchanged.
Certain interlock mechanism exist to prevent unwanted overwriting of important functions i.e. voltage regulators
or oscillator adjustments. These mechanisms are described with the functions of these registers.
*1) “shorted to ...”
18/35
L4969
2
CONTROL AND STATUS REGISTERS
The functionality of the device can be observed and controlled through a set of registers which are read and
writable by the serial interface.
2.1
ADR 0: VRCR Voltage Regulator Control Register
Figure 11.
D7
EUV3
D0
EUV2
RTC0
TRC
RES
Has to be
written as ‘0’.
Enable undervoltage
detection on
Regulator #2 and #3
(see note below)
Enable Regulator #2 tracking option
to have V2 following V1 with constant offset
Default value is ‘0’ (disabled)
Enable Regulator #3 .
V3 will be activated by either setting ENV3 or
upon enabling of the CAN Lineinterface
Default value is ‘0’ (disabled)
This bit will be automatically reset upon
Overtemperature from CANIF or Regulator #3
V1
ENV2
DISAR
Disable all Regulators (Go to Sleep)
Note, that at least one Wakeup Source
without a pending wakeup is required
to enable access.
This bit will be automatically set upon
the system failures Overtemperature V1
or watchdog startup failure.
Set reset threshold value to 4.0V
Default value is ‘0’ (4.5V)
DISAR
ENV3
Note, that no reset will be generated
from low V1 during Sleep mode transition
The Reset line has to be forced low
externally, or through a window failure
DISAR will be cleared upon a valid
wakeup signal which is either defined
in GIEN or is forced to WAKE or CAN
after a system failure
Enable Regulator #2.
Default value is ‘0’ (disabled)
This bit will be automatically reset upon
Overtemperature at Regulator #2.
Note, that due to the large initial charging current of the output capacitors,
the activation of V2 AND V3 within the same command is not recommended
also leaving ENV2 or ENV3 set when setting DISAR can therefor not be
recommended (after wakeup V1 AND V2 or V3 would be turned on)
TRC
DISAR & ENV2
(DISAR & ENV3 |
ACT)
& TSDV3
REF
V2
V3
V3 will be activated upon VRCR.ENV3 or
CCTR.ACT without pending thermal shutdown
Note, that when using the Undervoltage-detection, EUV2 and EUV3 have to be activated AFTER V2 or V3 have
been turned on and settled (t > 1ms). Otherwise unwanted undervoltage can be detectected during turn on of
the corresponding voltage regulator.
19/35
L4969
2.2
ADR 1: CTCR CAN-Transceiver Control Register
Figure 12.
D7
D0
ACT
TXEN
RES
RES
RES
LP2
LP1
LP0
Standby-mode control (V1 only, see 1.1)
CAN-Transceiver application control
enable Auto-Osc-Off
reduce Osc-frequency to 250KHz
0X : Standby / Sleep
10 : Receive only mode A (Readback TX, if not EX)
11 : Normal Operation
Note, that TXEN is automatically reset upon
occurence of EX (TX permanent dominant)
and has to be reprogrammed after problem
correction to enter normal mode.
Reserved bits (‘RES’) have to be written as ‘0’.
Three basic operating modes are available using different logic combinations on ACT and TXEN. Each of these
modes in conjunction with other inputs has its unique combination of parameters inside the specification:
Table 6.
Operating Modes of the CAN Lineinterface
Input Signals
Output Signals
ACT
TXEN
TX
CANH
CANL
V3
Mode
RTL
RTH
CANH
CANL
RX
0
X
X
RTH
RTL
ON
Standby
VBAT
GND
OFF
OFF
1
1
0
1/0
RTH
RTL
ON
RXonly
VDD
GND
OFF
OFF
TX
1
0
1
RTL
ON
RXonly
VDD
GND
OFF
OFF
1
0
1
RTH
ON
RXonly
VDD
GND
OFF
OFF
1
1
1
RTH
RTL
ON
Normal
VDD
GND
ON
ON
1
1
1
0
RTH
RTL
ON
Normal
VDD
GND
VDD
GND
0
1
1
1
RTL
ON
Normal
VDD
GND
ON
ON
1
1
1
RTH
ON
Normal
VDD
GND
ON
ON
1
1
*1
RTH
RTL
ON
Error X
VDD
GND
OFF
OFF
1
1
X
1
VDD*1
RTL
ON
Error
VII, VIII
VDD
ISRC
OFF
ON
CANL
1
X
1
VS*1
RTL
ON
Error
EIII, VII, VIII
VDD
ISRC
OFF
ON
CANL
1
X
1
GND
ON
Error
EI_V
VDD
GND
ON
ON
1
X
1
VDD
ON
Error
EII_IX
VDD
GND
ON
ON
1
X
1
RTH
VS*1
ON
Error
EVI
ISRC
GND
ON
OFF
CANH
1
X
1
RTH
GND*1
ON
Error
EVII, EIV
ISRC
GND
ON
OFF
CANH
1
X
1
CANL*1
CANH*1
ON
Error
EVII
ISRC
GND
ON
OFF
CANH
20/35
0
x3
x3
L4969
2.3
ADR 2: GPTR Global Parameter and Test Register
Figure 13.
D7
RES
D0
RES
RES
RES
TM1
TM0
TMUX
TEN
This register is to be used for testpurpose only, all bits have to remain ‘zero’
2.4
ADR 3: RCADJ RC-Oscillator Adjust register
Figure 14.
D0
D7
CG1
CG0
PGEN
ADJ4
ADJ3
ADJ2
ADJ1
ADJ0
0: 0%
0: 0%
1: +16% 1: -8%
0: 0%
1: -4%
0: 0%
1: -2%
0: 0%
1: -1%
Program enable (read only)
Bit will be set after 'Finish cycle measurement',
and reset after register write
Test cycle request
A low pulse on NINT
for a fixed period
of time can be requested
for XTAL synchronization
99AT0022
RC Oscillator
Frequency Adjust
default value 10000
Note, that programming
is only enabled with PGEN set
00: No request (Adjustment disabled)
01: 2.5ms low cycle on NINT (repetitive)
10: Finish cycle measurement
11: No request (Adjustment disabled)
During normal operation the µC can set CG1 and CG0 to ‘01’ to force a 200Hz rectangular waveform on NINT
with 50% duty cycle. Note, that all other pending interrupts have to be cleared before.
After the XTAL driven timer of the µC calculated the relative cycle time and the corresponding deviation,
CG1 and CG0 have to be set to ‘10’ to disable the adjustment cycle on NINT. From the deviation calculated by
the µC, the correction factor of the RC-oscillator -15% to + 16% can be reprogrammed with CG1 and CG0 set
to ‘00’ or ‘11’. (‘11’ can be used to indicate that calibration has already been performed).
Note, that overwriting this register is only valid, if the cycle measurement was started and terminated properly.
This can be tested by evaluating PGEN either prior to or during correction (Read back via SOUT).
Note also, that any write to the WDC register will reset the timer and thus reset the phase of the testcycle. Therefore a cyclic access to the window watchdog during the pulsewidth measurement has to be avoided and the
timer watchdog to be used instead (i.e. 1sec)
21/35
L4969
Figure 15.
State transition during oscillator calibration
“No Request”
CG=00
CG=01 “2.5ms cycle CG=10
“Finish
Cycle”
“Update ADJ”
on NINT”
CG=11
Watchdog and Interrupt
has to be disabled
2.5
Start time measurement
at rising edge
Calculate
Write offset
Offset Watchdog and Interrupt can be enabled
ADR4: WDC Watchdog Control Register
Figure 16.
D7
WDEN
D0
WND
SWT1
Disable
Window Watchdog,
only allowed with
PGEN set, see
previous table
for Osc adjust
Enable Wakeup Watchdog,
Window Watchdog will be
automatically deactivated
until wakeup watchdog expires
SWT0
WDT3
WDT2
Software Window Watchdog
timing configuration
00 : 2.5 - 5ms
01 : 5 - 10ms
10 : 10 - 20ms
11 : 20 - 40ms
Reserved bits (‘RES’) have to be written as ‘0’.
WDT1
WDT0
Wakeup Watchdog
timing configuration
0000 : 80ms
0001 : 160ms
0010 : 320ms
0011 : 640ms
0100 : 800ms
1000 : 1sec
1001 : 2sec
1010 : 4sec
1011 : 8sec
1100 : 45min
The Startup Watchdog is not programmable and will always generate a 1.0ms low cycle on NRESET followed
by a 320ms high cycle until an Acknowledgment will occur. If no Acknowldege is received after the 7th cycle,
the device will automatically be forced into Sleep mode.
Acknowledgment and Reset of Startup and Window Watchdog is automatically performed by overwriting
(or rewriting) this register.
Note, that with WDEN set, a cyclic setting of IFR.WKW after the programmed Wakeup time will occur.
2.5.1 Watchdog configuration:
22/35
L4969
Figure 17.
POR
NRESET
forced low
externally
ExtWake
CAN-Wake
Startup missing Ack Forced
Sleep
Wd (after 350ms)
Wakeup
Prog
Sleep
Ack
Ack
missing
Ack
Timeout
Window
WR
Wakeup
Wd WR & WDEN Timer
Note: WR, writing to this address, will restart the timer
After power-on-reset of VS and V1 or wakeup from Sleep or NRESET being forced low externally, the Startup
Watchdog is active, supervising the proper startup of the V1 supplied uC. Upon missing SPI write operation to
the WDC register after 7 reset cycles (1ms active, 320ms high) the Sleep mode is entered.
Leaving the forced Sleep mode will be automatically performed upon wakeup via CAN, an edge on WAKE or
upon device powerup.
After successful startup, the Window Watchdog supervision is activated, meaning, that the uC has to send an
acknowledge within a predefined, programmable window.
Upon failure, a reset is generated and the Startup Watchdog is reactivated.
If the Timer function is requested, the window watchdog is deactivated until expiry of the wakeup time, or rewriting of this register. Note, that any write to this register will reset the timer.
2.5.2 Startup
Figure 18.
V1
1ms
NRESET
Startup Acknowledgement via SPI within 320ms
NRESET
Startup Acknowledgement via SPI within 640ms
NRESET
No Startup Acknowledgement via SPI within 2.3s (Device will enter Sleep mode)
After powerup, the L4969 is expecting the uC to send an acknowledgement within a predefined segmented timing frame of 7 x 320ms. A missing acknowledgement until after the 2.3s will force the device into sleep mode
until either external or CAN wakeup or POR cause a restart of the sequence above.
2.5.3 Window Watchdog
23/35
L4969
Figure 19.
2,5 .. 20ms
50%
Early (late) Acknowlede supervision
5 .. 40ms
Early (late) Acknowlede supervision
Acknowledge is restarting Window
After successful acknowledgement of the Startup sequence, the Window watchdog is automatically activated
and controlling proper uC activity by supervising an incoming acknowledge to ly within a predefined programmable window. Upon every acknowledge the watchdog is restarting the window.
24/35
L4969
2.5.4 Wakeup Watchdog
Figure 20.
Window Wd
Timer (80ms .. 45min)
Ack Window &
Start Timer
NINT
restart timer
at any time
writing WDC twice
Window Wd
Timeout and resume Window Wd
Interrupt active upon timeout (via GIEN)
If the Timer is activated during Normal mode by setting WDEN in WDC, an “acknowledge-free” sequence is
started for a predefied programmable time. Window Watchdog activity is resumed after expiry of the timer.
To be able to detect the timeout, the corresponding interrupt enable must be set in GIEN.
This mode can also be used to allow a bootstrap loader mode with longer execution times than the maximum
specified window. Correct startup of this loader is safely detected upon missing response following the timeout.
The timer can always be restarted by rewriting WDEN twice in WDC with a new timing.
25/35
L4969
2.6
ADR5: GIEN Global Interrupt Enable Register
Figure 21.
D7
D0
ISET
IRES
EUV
EOVT
EEW
ECW
EWW
EIFW
Enable Identifier
based wakeup / Interrupt
Enable Interrupt
upon CAN error
detection
Enable Wakeup,/ Interrupt
via Watchdog
Enable CAN
wakeup / Interrupt
Enable Interrupt
upon CAN error
recovery
Enable
Interrupt
upon VS / VREG
Undervoltage
2.7
Enable Wakeup / Interrupt
via edge on WAKE
Enable Interrupt
upon Overtemp.
Warning
ADR6: IFR Interrupt Flag Register
Figure 22.
D11
D0
ESPI
ISET
IRES
CAN Linefailure
detected (ISET)
removed (IRES)
CRC- / Format
Error or SCLKTimeout detected
by SPI (non maskable)
UV23
UVVS OVT3 OVT2 OVT1
VS < 7.2V
detected
V2 or V3
Undervoltage
WKE
WKC
WKW
WKIF
Signal edge
on WAKE
detected
Overtemperature
Warning level reached
OVT1 : T(V1) > 140degC
OVT2 : T(V2) > 140degC
OVT3 : T(V3) > 140degC
Wakeup condition
via CAN detected
Watchdog timeout
detected
Identifier passed
CAN ID-Filter
Reserved bit (‘RES’) has to be written as ‘0’.
Except ESPI all bits in this register are maskable in GIEN. Any masked bit will force NINT low until the register
content is reset (either explicitly or by SPI ‘clear register).
26/35
L4969
2.8
ADR7: CTSR CAN Transceiver Status Register
Figure 23.
D11
RES
D0
RES
RES
GSH
EX
EVIII
CANH < -1V
at falling edge TX
TX permanent
dominant detected
(TXD = ‘0’, t > 1.3ms)
CANH permanent
dominant detected
(CANH > 1.8V, t > 1.3ms)
EVII
EVI
EIV
CANL short
circuit to VS
detected
(CANL > 7.2V,
t > 32us)
CANL permanent
dominant detected
(CANL < 3.1V,
t > 1.3ms)
Short circuit CANH to CANL detected
(CANH - CANL > -3.25V, t > 1.3ms)
EIII
EII_IX
EI_V
Single wire
communication
detected
(edge count
difference > 3)
EI_V : CANH off
EII_IX : CANL off
CANH short
circuit to VS
detected
(CANH > 7.2V,
t > 32us)
Reserved bits (‘RES’) are always read as ‘0’
Note, that this register is read only and only provides the unlatched information on current buserrors.
27/35
L4969
2.9
ADR 8 and 9: ID01, ID23 Identifier Filter Sequence Select Register
Figure 24.
SEGA
ID10
ID9
SEGB
ID8
ID7
SEGC
ID6
SEGD
ID5
ID4
ID3
SEGE
ID2
ID1
SEGF
ID0
RTR
SOF
4/2
Demux
4/2
Demux
00
00
A00
F00
A01
F01
A10
F10
11
A11
11
F11
PASS
99AT0028
Identifier of CAN Frame can be divided up into 6 segments numbered from ‘A’ to ‘F’.
For each segment a filter register is implemented, enabling different pass functions on every two bit wide block.
Segments A through C (ID01) are located at ADR 8 with MSB ‘C11’
Segments D through F (ID23) are located at ADR 9 with MSB ‘F11’
Note, that clearing a complete segment disables the whole filter.
SEGE
SEGD SEGF
Examples:
10 01 00
Identifiers to pass: 10 01 01
00 01 01
01 01 01
01 11 01
10 00 10
SEGA SEGC
SEGB
28/35
Valid sequence
for each segment
SEGA: A10, A00
SEGB: B01
SEGC: C01, C00
SEGD: D10, D01
SEGE: E11, E01, E00
SEGF: F10, F01
ID bits to be set
0101
0010 ID01: 0011 0010 0101
0011
0110
1011 ID01: 0110 1011 0110
0011
L4969
2.10 ADR 10: BTL Identifier Filter Bittimelogic Control Register
Figure 25.
D11
PS23
D0
PS22
PS21
Phasesegment 2
length configuration
tPSEG2 = 1us * PSEG2
PS2
PS13
PS12
PS11
PS10
Phasesegment 1
length configuration
tPSEG1 = 1us * (1 + PSEG1)
TD3
TD2
TD1
TD0
Dominant to Rezessive
bitlength difference control
td = tdom - trez
Bittime synchronization mechanism
t = 1u
tPSEG2
tPSEG1
Sample Point
99AT0030
The total bitlength equals the sum of 1 + PSEG1 + PSEG2 in units of µs.
The location of the sampling point is determined by the length of PSEG1.
At the start of frame (initial recessive to dominant edge) the bitlength counter is reset.
Upon every signal edge the counter will be lengthened or shortened according to location of the transition within
the programmed boundaries of PSEG1 or PSEG2. If the edge lies within PSEG1 additional cycles are inserted
in order to shift the sampling point to a safe location after the settling of the input signal. If the signal transition
is located within PSEG2, this segment will be shortened accordingly with the goal of the next edge to lie at the
beginning of PSEG1.
The amount of cycles one segment is lengthened or shortened is determined by the type of edge (rec -> dom
or dom -> rec) and the programming of TD: The resynchronization jump width will be either set to ‘1’ (dom ->
rec edge) or to 1 + TD (rec -> dom edge).
Note, that the length of one timequanta depends on the offset of the on chip RC-oscillator and therefore on the
accuracy of calibration (see register RCADJ (ADR 3) for details on frequency correction)
29/35
L4969
2.11 ADR 15: SYS System Status Register
Figure 26.
D7
NCRC
D0
STAT
WNDF
STF
OTF
UCF
WAKE
NPOR
Cold Start
after low VS
CRC-Checking
disabled
Reserved
status flag
(test only)
Warm start
after failure of
Window watchdog
Warm start
after V1
Overtemp failure
Warm start
after < 7 missing
Ack during Startup
Warm start
after leaving
prog. Sleep mode
Warm start
after 7 missing
Ack during Startup
The lower 6 bit of this register can be used to analyze the reason of startup (after NRESET low). This information
is valid until the first Watchdog-Acknowldge, and will then be reinitialized to 000001.
30/35
L4969
3
INTERRUPT MANAGEMENT
Figure 27.
IFR
D11
ESPI ISET
IRES
UV23
UVVS
ISET
D7
OVT3
D0
OVT2 OVT1 WKE
WKC
WKW WKIF
EEW
ECW
EWW EIFW
IRES EUV
EOVT
GIEN
D0
NINT
All Interrupt flags (in IFR) except ESPI can be masked in the global interrupt enable register (GIEN).
An Interrupt will be signalled by NINT going low until either the corresponding mask or the flag itself will be reset
by the application software. An autoreset function is available for IFR, allowing to remove all interrupt flags after
reading their state (see SPI).
31/35
L4969
4
REMARKS FOR APPLICATION
Figure 28. General circuit connection diagram
VS
Thermal
Supervision
*
10u
47n
Peripheral
Supply
V2
*
47n
Standby Supply
& Adjustable
RC-Oscillator
10u
V1
120K
Programmable
Timer
*
47n
10u
NRES
opt
NINT
Wakeup & Interrupt
Detection
WAKE
C
µ
V3
33u
SPI
*
SCLK
SIN
SOUT
47n
RX
*
RTH
CAN
Transceiver
CANH
CANL
Groundshift
Detection
47p
*
47p
RTL
ID-Filter
GND
99AT0032
C* ceramic C close to pin recommended for EMI
32/35
TX
L4969
mm
inch
OUTLINE AND
MECHANICAL DATA
DIM.
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
2.35
2.65
0.093
0.104
A1
0.1
0.3
0.004
0.012
B
0.33
0.51
0.013
0.020
C
0.23
0.32
0.009
0.013
D
12.6
13
0.496
0.512
E
7.4
7.6
0.291
0.299
e
1.27
0.050
H
10
10.65
0.394
0.419
h
0.25
0.75
0.010
0.030
L
0.4
1.27
0.016
0.050
SO20
K
0˚ (min.)8˚ (max.)
L
h x 45˚
A
B
e
A1
K
C
H
D
20
11
E
1
0
1
SO20MEC
33/35
L4969
DIM.
mm
MIN.
TYP.
A
a1
inch
MAX.
MIN.
TYP.
3.6
0.1
0.142
0.3
a2
0.004
0.012
3.3
0.130
a3
0
0.1
0.000
0.004
b
0.4
0.53
0.016
0.021
0.013
c
0.23
0.32
0.009
D (1)
15.8
16
0.622
0.630
D1
9.4
9.8
0.370
0.386
E
13.9
14.5
0.547
0.570
e
1.27
e3
11.43
E1 (1)
10.9
0.450
0.429
0.437
2.9
0.114
E3
5.8
6.2
0.228
0.244
G
0
0.1
0.000
0.004
H
15.5
15.9
0.610
h
L
0.626
1.1
0.8
JEDEC MO-166
0.043
1.1
N
Weight: 1.9gr
0.050
11.1
E2
OUTLINE AND
MECHANICAL DATA
MAX.
0.031
0.043
8˚ (typ.)
S
8˚ (max.)
T
10
0.394
PowerSO20
(1) “D and E1” do not include mold flash or protusions.
- Mold flash or protusions shall not exceed 0.15mm (0.006”)
- Critical dimensions: “E”, “G” and “a3”.
N
R
N
a2
b
A
e
DETAIL A
c
a1
DETAIL B
E
e3
H
DETAIL A
lead
D
slug
a3
DETAIL B
20
11
0.35
Gage Plane
-C-
S
SEATING PLANE
L
G
E2
E1
BOTTOM VIEW
C
(COPLANARITY)
T
E3
1
h x 45
10
PSO20MEC
D1
0056635
34/35
L4969
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
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35/35