NXP Semiconductors MPC5644A, Reference Manual, Page: 721 / 1735

Reaction Module (REACM)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 721
In case of several timer activation requests being issued at the same time, the logic in the Timer Bank will
prioritize giving higher priority for the channel with lower number, thus channel zero has higher priority
than the others. No flags are set in the case several requests are issued simultaneously unless there are more
requests than the number of available timers. In this case the TAER error flag is set in the requesting
channel status register.
Figure 23-21 presents a block diagram of the Timer Bank.
Figure 23-21. Shared timer bank block diagram
23.4.4 Hold-off timer bank
The Hold-off Timer Bank stores time values that are used by the hold-off periods during the modulation
process. This bank is shared among all channels and is addressed based on the HDOFFPT pointer in the
Modulation Control Word.
Figure 23-22 shows a block diagram of this bank and its interconnections.
TIMER
ALLOCATION
TIMER0
Channel Timer
TIMER1
TIMER2
TIMER
SELECTION
CHANNEL
CHANNEL[15:0]
Timer value Pointer [3:0]
SHARED TIME BANK
Timer Error indication
CPU
allocation Request [15:0]
in case no timer is available
timeout indication
(back to channel)
set channel TAERR flag
ch tag
ch tag
ch tag
4
4
4
allocation req/ack
allocation req/ack
allocation req/ack
4
4
4
timeout
timeout
timeout
sel channel
LOGIC
16 16 16
16
one line per
channel
one line per channel
shared timer 0
shared timer 1
shared timer 2