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 Timer (TIM) 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 TIM 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_TIM 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.
Timer module
The basic timer consists of a 16-bit, software-programmable counter driven by a seven-stage
programmable prescaler. This timer contains 8 (or 6) complete input capture/output compare channels and one pulse accumulator. The
input capture function is used to detect a selected transition edge and record the time. The output compare
function is used for generating output signals or for timer software delays. The 16-bit pulse accumulator
is used to operate as a simple event counter or a gated time accumulator. The pulse accumulator shares
timer channel 7 when in event mode.
A full access for the counter registers or the input capture/output compare registers should take place in
one clock cycle. Accessing high byte and low byte separately for all of these registers may not yield the
same result as accessing them in one word.
The timer includes these distinctive features:
- Eight (or six) input capture/output compare channels.
- Clock prescaling.
- 16-bit counter.
- 16-bit pulse accumulator.
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
