MCF5253CVM140J Freescale Semiconductor, MCF5253CVM140J Datasheet - Page 626

• Manufacturer Part Number: MCF5253CVM140J
• Description: IC MCU 2.1MIPS 140MHZ 225MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: MCF525xr

Specifications of MCF5253CVM140J

• Core Processor: Coldfire V2
• Core Size: 32-Bit
• Speed: 140MHz
• Connectivity: CAN, EBI/EMI, I²C, QSPI, UART/USART, USB OTG
• Peripherals: DMA, WDT
• Program Memory Type: ROMless
• Ram Size: 128K x 8
• Voltage - Supply (vcc/vdd): 1.08 V ~ 1.32 V
• Data Converters: A/D 6x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 225-MAPBGA
• Processor Series: MCF525x
• Core: ColdFire V2
• 3rd Party Development Tools: JLINK-CF-BDM26, EWCF
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details

FlexCAN Module
25-10
PROPSEG
BOFFREC
TSYN
LBUF
Field
11–8
SMP
LOM
LPB
2–0
12
7
6
5
4
3
Loop back. Configures FlexCAN to operate in loop-back mode. In this mode, FlexCAN performs an internal loop
back that can be used for self test operation. The bit stream output of the transmitter is fed back internally to the
receiver input. The Rx CAN input pin is ignored and the Tx CAN output goes to the recessive state (logic 1).
FlexCAN behaves as it normally does when transmitting, and treats its own transmitted message as a message
received from a remote node. In this mode, FlexCAN ignores the bit sent during the ACK slot in the CAN frame
acknowledge field, generating an internal acknowledge bit to ensure proper reception of its own message. Both
transmit and receive interrupts are generated.
0 Loop back disabled
1 Loop back enabled
Reserved, should be cleared.
Sampling mode. Determines whether the FlexCAN module will sample each received bit one time or three times to
determine its value.
0 One sample, taken at the end of phase buffer segment 1, is used to determine the value of the received bit.
1 Three samples are used to determine the value of the received bit. The samples are taken at the normal sample
Bus off recovery mode. Defines how FlexCAN recovers from bus off state. If this bit is cleared, automatic recovering
from bus off state occurs according to the CAN Specification 2.0B. If the bit is set, automatic recovering from bus
off is disabled and the module remains in bus off state until the bit is cleared by the user. If the bit is cleared before
128 sequences of 11 recessive bits are detected on the CAN bus, then bus off recovery happens as if the
BOFFREC bit had never been set. If the bit is cleared after 128 sequences of 11 recessive bits occurred, then
FlexCAN will re-synchronize to the bus by waiting for 11 recessive bits before joining the bus. After clearing, the
BOFFREC bit can be set again during bus off, but it will only be effective the next time the module enters bus off.
If BOFFREC was cleared when the module entered bus off, setting it during bus off will not be effective for the
current bus off recovery.
0 Automatic recovering from bus off state enabled, according to CAN Spec 2.0B
1 Automatic recovering from bus off state disabled
Timer synchronize mode. Enables the mechanism that resets the free-running timer each time a message is
received in Message Buffer 0. This feature provides the means to synchronize multiple FlexCAN stations with a
special “SYNC” message (global network time).
0 Timer synchronization disabled.
1 Timer synchronization enabled.
Note: There can be a bit clock skew of four to five counts between different FlexCAN modules that are using this
feature on the same network.
Lowest buffer transmitted first. Defines the ordering mechanism for message buffer transmission.
0 Message buffer with lowest ID is transmitted first
1 Lowest numbered buffer is transmitted first
Listen-only mode. Configures FlexCAN to operate in listen-only mode. In this mode transmission is disabled, all
error counters are frozen, and the module operates in a CAN error passive mode. Only messages acknowledged
by another CAN station will be received. If FlexCAN detects a message that has not been acknowledged, it will flag
a BIT0 error (without changing the REC), as if it was trying to acknowledge the message.
0 FlexCAN module is in normal active operation; listen-only mode is deactivated
1 FlexCAN module is in listen-only mode operation
Propagation segment. Defines the length of the propagation segment in the bit time. The valid programmable
values are 0–7.
Note: A time-quantum = 1 S clock period.
Propagation segment time
Table 25-3. FlexCAN Control (CANCTRLn) Register Field Descriptions (continued)
point and at the two preceding periods of the S-clock; a majority rule is used.
=
(PROPSEG + 1) time-quanta
MCF5253 Reference Manual, Rev. 1
Description
Freescale Semiconductor