PXD20 Datasheet, PDF (18/130 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Overview
• Programmable data frames from 4 to 16 bits
• Up to 3 chip select lines available, depending on package and pin multiplexing, enable 8 external devices to be selected
using external muxing from a single SPI
• Eight clock and transfer attributes registers
• Chip select strobe available as alternate function on one of the chip select pins for de-glitching
• FIFOs for buffering up to 4 transfers on the transmit and receive side
• General purpose I/O functionality on pins when not used for SPI
• Queueing operation possible through use of eDMA
1.4.23 Controller Area Network (CAN) module
The PXD20 includes up to three controller area network (CAN) modules. The CAN module is a communication controller
implementing the CAN protocol according to Bosch Specification version 2.0B. The CAN protocol was designed to be used
primarily as a vehicle serial data bus, meeting the specific requirements of this field: real-time processing, reliable operation in
the EMI environment of a vehicle, cost-effectiveness and required bandwidth.
Each CAN module offers the following:
• Compliant with CAN protocol specification, Version 2.0B active
• 64 mailboxes, each configurable as transmit or receive
— Mailboxes configurable while module remains synchronized to CAN bus
• Transmit features
— Supports configuration of multiple mailboxes to form message queues of scalable depth
— Arbitration scheme according to message ID or message buffer number
— Internal arbitration to guarantee no inner or outer priority inversion
— Transmit abort procedure and notification
• Receive features
— Individual programmable filters for each mailbox
— 8 mailboxes configurable as a 6-entry receive FIFO
— 8 programmable acceptance filters for receive FIFO
• Programmable clock source
— System clock
— Direct oscillator clock to avoid PLL jitter
• Listen only mode capabilities
• CAN Sampler
— Can catch the 1st message sent on the CAN network while the MCU is stopped. This guarantees a clean startup
of the system without missing messages on the CAN network.
— The CAN sampler is connected to one of the CAN RX pins.
1.4.24 Serial communication interface module (UART)
The PXD20 devices include up to four UART modules and support for UART Master mode, UART Slave mode and UART
mode. The modules are UART state machine compliant to the LIN 1.3 and 2.0 and 2.1 Specifications and handle UART frame
transmission and reception without CPU intervention.
The serial communication interface module offers the following:
• UART features:
— Full-duplex operation
— Standard non return-to-zero (NRZ) mark/space format
PXD20 Microcontroller Data Sheet, Rev. 2
18
Preliminary—Subject to Change Without Notice
Freescale Semiconductor