mc33742 Freescale Semiconductor, Inc, mc33742 Datasheet - Page 34

• Manufacturer Part Number: mc33742
• Description: Mc33742 System Basis Chip Sbc With Enhanced High-speed Can Transceiver
• Manufacturer: Freescale Semiconductor, Inc

TXD AND RXD PINS
depends on the V2 status. RXD is a push-pull structure,
supplied by V2. When V2 is set at 5.0 V and CAN is TXRX
mode, RXD reports bus status. For details, refer to
page 25,
Table 9. CAN Interface / 33742S Modes and Pin Status—Operation with Ballast on V2
34
33742
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
Notes
Reset (with Ballast)
44.
Normal Request
The TXD pin has an internal pullup to V2. The state of TXD
External Ballast
(with Ballast)
Standby with
Unpowered
Normal
Normal
Mode
Sleep
See also
Stop
Table 9
Figure 31,
, below, and
(Controlled by SPI)
Slew Rate 0, 1, 2, 3
Normal or Sleep
CAN Mode
page 52.
Normal
Sleep
Sleep
Sleep
–
–
–
Table 10
CAN Recessive State
CANH
CANL
RXD
TXD
, page 35.
V2 Voltage
0.0 V
0.0 V
0.0 V
5.0 V
5.0 V
0.0 V
0.0 V
0.0 V
Typ 2.5 V
Typ 2.5 V
Figure 20. CAN Interface Levels
Table 7
Internal Pullup
TXD Pin
V
,
0.0 V
to V2
LOW
LOW
LOW
LOW
LOW
LOW
CANH
CAN Dominant State
-V
CANL
CAN TXRX MODE AND SLEW RATE SELECTION
Tables 21
available and control the recessive-to-dominant and
dominant-to-recessive transitions. The delay time from TXD
pin to CAN bus, from CAN bus to RXD, and from the TXD to
RXD loop time is affected by the slew rate selection.
The slew rate selection is done via CAN register (refer to
Report Bus State
LOW if dominant
> 900 mV
HIGH if Bus
Recessive,
RXD Pin
LOW
LOW
LOW
5.0 V
LOW
LOW
LOW
through
CAN Recessive State
23
CANH = CANL = 2.5 V
V
(Disconnected from
on page 45). Four slew rates are
CANH
Analog Integrated Circuit Device Data
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
Other Node)
(44)
-V
CANL
< 500 mV
Freescale Semiconductor
Wake-up if enabled
Wake-up if enabled
Communication
CAN
YES
NO.
NO.
NO
NO
NO
NO
NO