NXP Semiconductors MPC5644A, Reference Manual, Page: 735 / 1735

Reaction Module (REACM)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 735
Figure 23-34. DMA Req/Done protocol
23.8 Reset overview
The Reaction Module is reset whenever any MCU reset occurs. In order to re-initialize the reaction
channels the CHEN, channel enable register should be used. Once disabled the channel output is set to
DOFF state and the channel configuration can be changed safely. The disable/enable operation does not
change the channel setup, thus the configuration registers remain at the state as before the channel was
disabled. The Modulation Control word addressed by the channel after the enable bit is asserted is defined
by the MODULATION ADDR field in the channel configuration register.
23.9 Reaction module interrupts
The Reaction Module issues one global interrupt signal and one interrupt signal per channel. If using the
Global interrupt signal the resolution of the interrupt source need to be performed by reading the Global
Error Flag register to evaluate which channel issued the interrupt. After that the Channel Status register
need to be read to distinguish between the several interrupt sources by evaluating the flags MAXL, OCDF,
SCDF, TAER, and SQER.
D
a b c e d f
timer
control
signal
Current in
Injector
time
time
OFF
ON
OFF
A B C E
modu
lation
w
o
rd
0
modu
lation
w
o
rd
1
modu
lation
w
o
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2
modu
lation
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3
modu
lation
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4
DMA DONE
signal
time
DMA REQ
signal
time