NXP Semiconductors MPC5644A, Reference Manual, Page: 703 / 1735

Reaction Module (REACM)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 703
23.3.7 REACM Channel n Configuration Register (REACM_CHCRn)
The REACM Channel n Configuration Register (REACM_CHCRn) controls the channel behavior.
Figure 23-9. REACM Channel n Configuration Register (REACM_CHCRn)
Address: REACM_BASE (0xC3FC_7000) + (n* 0x0000) Access: User read/write
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R
CHEN[1:0]
SWMC
MAXLEN
OC
DFEN
SCDFEN T
AEREN
SQEREN RAEREN
DMAEN
CH
OFF
0 0
DOFF[2:0]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R 0 0 0 0 0
BSB[2:0]
0 0
MODULATION _ADDR[5:0]
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Table 23-9. REACM_CHCRn field descriptions
Field Description
0–1
CHEN[1:0]
Channel Enable Bits
The CHEN[1:0] bits control the activation of the reaction channel. Once changed from
disabled , CHEN = 00, to any enabled state, the channel reads the first Modulation Word
and initializes itself in order to be ready to execute a modulation as soon as a timer control
window is detected or SWMC = 1, if software modulation control is selected by
CHEN = 11.
00 Channel disabled, meaning that it does not execute any modulation even if a timer
window is detected or SWMC is made active. In this mode DOFF field in the
REACM_CHCR defines the state of the channel outputs.
01 Channel is enabled for timer control only, meaning that as soon as a timer window is
detected a modulation sequence starts.
10 Reserved
11 Channel enabled for software control only, meaning that as soon as SWMC bit is set
a modulation sequence starts.
Note: If CHEN is programed with 01 or 11 enabling a channel, and the eTPU time window
is already active (or SWMC = 1), the reaction channel disregards this window and
waits until the next window activation in order to start the modulation process by
moving to the active state. In order to start a modulation controlled by software, it
is necessary to first write CHEN = 1 and only after that write SWMC = 1.
2
SWMC
Software Modulation Control bit
If this bit is set, the channel initiates a modulation. It is equivalent to the assertion of an
eTPU channel connected to the Reaction module. In order for this functionality to be used
it is required that CHEN[1:0] = 11.
1 Channel executes modulation
0 Channel does not perform modulation