PXN20RM Datasheet, PDF (622/1376 Pages) Freescale Semiconductor, Inc – PXN20 Microcontroller

FlexRay Communication Controller (FlexRAY)
To avoid this,
• The application should not send the CHI command FREEZE and use the
CHI command HALT instead.
• Before sending the CHI command FREEZE the application should
repeatedly disable all message buffers until all message buffers are
disabled. This maximum duration of this task is three static or three
dynamic slots.
26.4 Protocol Engine Clocking
The clock for the protocol engine can be generated by two sources. The first source is the internal crystal
oscillator and the second source is an internal PLL. The clock source to be used is selected by the clock
source select bit CLKSEL in the Module Configuration Register (MCR).
26.4.1 Oscillator Clocking
If the protocol engine is clocked by the internal crystal oscillator, a 40 MHz crystal or CMOS compatible
clock must be connected to the oscillator pins. The crystal or clock must fulfill the requirements given by
the FlexRay Communications System Protocol Specification, Version 2.1 Rev A.
26.4.2 PLL Clocking
26.5 Memory Map and Register Description
The controller occupies 1280 bytes of address space starting at the controller’s base address defined by the
memory map of the MCU.
26.5.1 Memory Map
The complete memory map of the controller is shown in Table 26-3. The addresses presented here are the
offsets relative to the controller base address which is defined by the MCU address map.
Table 26-3. FlexRay Memory Map
Offset
0x0000
0x0002
0x0004
0x0006
0x0008
0x000A
0x000C
0x000E
Register
Module Configuration and Control
Module Version Register (MVR)
Module Configuration Register (MCR)
System Memory Base Address High Register (SYMBADHR)
System Memory Base Address Low Register (SYMBADLR)
Strobe Signal Control Register (STBSCR)
Reserved
Message Buffer Data Size Register (MBDSR)
Message Buffer Segment Size and Utilization Register (MBSSUTR)
Test Registers
Access
R
R/W
R/W
R/W
R/W
R
R/W
R/W
26-8
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor