Peripheral Beans cover all the hardware functionality and they are intended for expert use of the respective
peripherals. This bean implements the peripheral initialization of an internal Byteflight (BYTEFLIGHT) module
of the Freescale HCS12 MCU derivatives.
Peripheral initialization
The bean contains no high level methods or events, it provides only initialization of the hardware module. By default is the internal
initialization called automatically from the "PE_low_level_init" in CPU module, analogous to the initialization of other
PE beans. However the calling of this init code in the CPU module can be disabled and the user may call this function in
another module.
If the initialization property
"Call init in CPU init.code" is set to
"no" then the initialization is removed
from the CPU module code and the user have to call the
'BeanName_Init()' function elsewhere, i.e. in the main module.
Interrupt service
Processor Expert generates interrupt service support of BYTEFLIGHT peripheral only for the interrupt vector which the ISR routine
name is specified for. Otherwise the interrupts are served by the default routine(s). The support include interrupt vector
hooking and priority setting for the respective interrupt vector.
The peripheral beans does not generate code for the interrupt service routines specified in the Interrupts properties group
of the Init_BYTEFLIGHT bean (see Bean Inspector window). If there are any of the interrupts enabled in the bean the user is responsible
for the handling of such ISR's. Correct interrupt service routine "ISR name" must be implemented in the user code.
Warning:
This is low level bean. Usually it is not possible to use one setting of this bean for different microcontrollers.
Byteflight module
The Byteflight module is the specific implementation of the BMW Byteflight concept targeted for the
Freescale microcontroller family. The device interfaces a microcontroller (MCU) and the optical
transceiver device Infineon (SPF BFT003) for receiving and transmitting messages according to latest
BMW Byteflight specification.
The Byteflight includes these distinctive features:
- Modular Architecture.
- Implementation of the BMW Byteflight protocol.
1 byte identifier.
1 byte data length field (4 bits length, 4 bits reserved).
0 12 bytes data.
2 bytes checksum, hardware CRC generation and checking.
bit rate 10 Mbps.
no collision on the bus.
non-return-to-zero (NRZ) format.
- Double buffered receive storage scheme.
- 16 Message Buffers of 0-12 bytes data length and 2 temporary receive buffers (RXFG, RXBG).
- Programmable Message Buffer Configuration (Transmit, Receive, FIFO).
- Content-related addressing.
- Receive FIFO for bus monitoring with programmable acceptance and rejection filter.
- 11 maskable interrupt sources, generating five CPU interrupt vectors.
- Programmable bus master function.
- Programmable wake-up function.
- Low power sleep mode.
Peripheral Initialization Beans provide a low-level hardware approach to
initialize registers of the peripheral module. They are intended for experienced users.
This bean belongs to the category: CPU Internal Peripherals-Peripheral Initialization Beans
