MC33989PEG Freescale Semiconductor, MC33989PEG Datasheet - Page 50

• Manufacturer Part Number: MC33989PEG
• Description: SBC-HS
• Manufacturer: Freescale Semiconductor

TYPICAL APPLICATIONS
SUPPLEMENTAL APPLICATION NOTES
CAN Mode versus SBC Modes
pins.
Table 34. CAN vs SBC Modes
How to Test the MC33989 CAN Interface
V1. The device is supplied with nominal supply (12 V at VSUP input pin). After power on, reset the device, enter normal request
mode, and the CAN interface is set in normal mode, slew rate 0. TX can be driven by a signal generator. RX will report the bus
state. The figure below is a simple test schematic.
50
33989
Unpowered
Reset (with ballast)
Normal request (with ballast)
Normal
Normal
Standby with external ballast
Standby without external
ballast, V2 connected to V1
Standby without external
ballast, V2 connected to V1
Sleep
Stop
The table below indicates the CAN interface modes versus the SBC modes as well as the status of TX, RX and the CAN bus
The CAN interface can be easily set up and tested. MC33989 can be connected as in the following figure. V2 is connected to
SBC mode
CAN bus
RT
Differential termination concept
CANH
CANL
(partial drawing)
External
ballast
for V2
YES
YES
YES
YES
YES
YES
NO
NO
MC33989
—
—
Gnd
Normal Slew rate
Normal or sleep
Sleep mode
CAN mode
Unpowered
TX
RX
Normal
0,1,2,3
Figure 37. Bus Termination
Sleep
Sleep
Sleep
voltage
5.0 V
5.0 V
5.0 V
5.0 V
0 V
0 V
0 V
0 V
0 V
0 V
V2
CAN bus
Internal pull-up
normal mode
Same as
to V2.
LOW
LOW
LOW
5.0 V
LOW
LOW
LOW
5 V
TX
RT /2
RT /2
Split termination concept
CANH
CANL
(partial drawing)
Analog Integrated Circuit Device Data
MC33989
Report bus state
recessive, Low if
Same as normal
Gnd
High if bus
dominant
mode
5.0 V
LOW
LOW
LOW
LOW
LOW
LOW
5 V
RX
Freescale Semiconductor
TX
RX
CANH = CANL =
Same as normal
(disconnected
Floating to gnd
Floating to gnd
Floating to gnd
Floating to gnd
Floating to gnd
Floating to gnd
Floating to gnd
Floating to gnd
Bus recessive
CANH/CANL
from other
nodes)
mode
2.5 V