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FlexRay Communication Controller (FlexRay)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1597
33.6.17 Timer support
The CC provides two timers, which run on the FlexRay time base. Each timer generates a maskable
interrupt when it reaches a configured point in time. Timer T1 is an absolute timer. Timer T2 can be
configured to be an absolute or a relative timer
.
Both timers can be configured to be repetitive. In the
non-repetitive mode, timer stops if it expires. In repetitive mode, timer is restarted when it expires.
Both timers are active only when the protocol is in
POC:normal active
or
POC:normal passive
state. If
the protocol is not in one of these modes, the timers are stopped. The application must restart the timers
when the protocol has reached the
POC:normal active
or
POC:normal passive
state.
33.6.17.1 Absolute timer T1
The absolute timer T1 has the protocol cycle count and the macrotick count as the time base. The timer 1
interrupt flag TI1_IF in the
Protocol Interrupt Flag Register 0 (FR_PIFR0)
is set at the macrotick start
event, if
are fulfilled
Eqn. 33-27
Eqn. 33-28
If the timer 1 interrupt enable bit TI1_IE in the
Protocol Interrupt Enable Register 0 (FR_PIER0)
is
asserted, an interrupt request is generated.
The status bit T1ST is set when the timer is triggered, and is cleared when the timer expires and is
non-repetitive. If the timer expires but is repetitive, the T1ST bit is not cleared and the timer is restarted
immediately. The T1ST is cleared when the timer is stopped.
33.6.17.2 Absolute / Relative timer T2
The timer T2 can be configured to be an absolute or relative timer by setting the T2_CFG control bit in the
Timer Configuration and Control Register (FR_TICCR)
. The status bit T2ST is set when the timer is
triggered, and is cleared when the timer expires and is non-repetitive. If the timer expires but is repetitive,
the T2ST bit is not cleared and the timer is restarted immediately. The T2ST is cleared when the timer is
stopped.
33.6.17.2.1
Absolute timer T2
If timer T2 is configured as an absolute timer, it has the same functionality timer T1 but the configuration
from
Timer 2 Configuration Register 0 (FR_TI2CR0)
Timer 2 Configuration Register 1 (FR_TI2CR1)
is used. On expiration of timer T2, the interrupt flag TI2_IF in the
Protocol Interrupt Flag Register 0
is set. If the timer 1 interrupt enable bit TI1_IE in the
Protocol Interrupt Enable Register 0
is asserted, an interrupt request is generated.
CYCTR CTCCNT
& FR_TI1CYSR T1_CYC_MSK
FR_TI1CYSR T1_CYC_VAL
& FR_TI1CYSR T1_CYC_MSK
=
FR_MTCTR MTCT
FR_TI1MTOR T1_MTOFFSET
=
Summary of Contents for MPC5644A
Page 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...