MPC563XM Reference Manual, Rev. 1
976
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
NMF[0:25]— Null Message Format
The NMF field contains the programmable null message send value for the EQADC. The value written
to this register will be sent as a null message when serial transmissions from the EQADC SSI are
enabled (ESSIE field configured to 0b11 in
Section 24.5.2.1, “EQADC Module Configuration
) and either
1. there are no triggered CFIFOs with commands bound for external CBuffers, or;
2. there are triggered CFIFOs with commands bound for external CBuffers but the external CBuffers
are full.
Refer to
Section , “Null Message Format for External Device Operation
for more information on the
format of a null message.
NOTE:
The EQADC Null Message Send Format Register only affects how the EQADC
sends a null message, but it has no control on how the EQADC detects a null
message on receiving data. The EQADC detects a null message by decoding the
MESSAGE_TAG field on the receive data. Refer to
on the MESSAGE_TAG field.
NOTE:
Writing to the EQADC Null Message Send Format Register while the serial
transmissions are enabled (ESSIE field configured to 0b11 in
“EQADC Module Configuration Register (EQADC_MCR)
24.5.2.4
EQADC External Trigger Digital Filter Register (EQADC_ETDFR)
The EQADC External Trigger Digital Filter Register (EQADC_ETDFR) is used to set the minimum time
a signal must be held in a logic state on the CFIFO triggers inputs to be recognized as an edge or level
gated trigger. The Digital Filter Length field specifies the minimum number of system clocks that must be
counted by the digital filter counter to recognize a logic state change. However, there is a control signal
that can be used to bypass the digital filter when this is not needed.
Figure 24-5. EQADC External Trigger Digital Filter Register (EQADC_ETDFR)
Register address: EQA0x00C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
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
0
0
0
0
0
0
0
DFL
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0