MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
567
Preliminary—Subject to Change Without Notice
17.4.2.5
Synthesizer FM Modulation Register (SYNFMMR)
This register controls the frequency modulation features of the FMPLL. FM modulation is not backwards
compatible with previous devices of the eSys family. Therefore, this register must be used in enhanced
mode. It can only be programmed when the FMPLL is locked. Writing to this register while the FMPLL
is unlocked has no effect. Furthermore, when the PLL loses lock, FM modulation is disabled and the
SYNFMMR register is reset.
9
LOLRE
Loss-of-lock reset enable. The LOLRE bit determines whether system reset is asserted or not upon a loss-of-lock
indication. When operating in normal mode, the FMPLL must be locked before setting the LOLRE bit, otherwise
reset is immediately asserted. Note that once reset is asserted, the operating mode is switched to bypass mode,
and once in bypass, a loss-of-lock condition does not generate reset, regardless of the value of the LOLRE bit. See
Section 17.5.3, “Lock Detection
0 Ignore loss-of-lock. Reset not asserted.
1 Assert reset on loss-of-lock when operating in normal mode.
10
LOCRE
Loss-of-clock reset enable. The LOCRE bit determines whether system reset is asserted or not upon a loss-of-clock
condition when LOCEN=1. LOCRE has no effect when LOCEN=0. If the LOCF bit in the SYNSR indicates a
loss-of-clock condition, setting the LOCRE bit causes immediate reset. In bypass mode with crystal reference, reset
will occur if the reference clock fails, even if LOCRE=0 or even if LOCEN=0. The LOCRE bit has no effect in bypass
mode with external reference. In this mode, the reference clock is not monitored at all. See
.
0 Ignore loss-of-clock. Reset not asserted.
1 Assert reset on loss-of-clock.
11
LOLIRQ
Loss-of-lock interrupt request. The LOLIRQ bit enables a loss-of-lock interrupt request when the LOLF flag is set.
If either LOLF or LOLIRQ is negated, the interrupt request is negated. When operating in normal mode, the FMPLL
must be locked before setting the LOLIRQ bit, otherwise an interrupt is immediately asserted. The interrupt request
only happens in normal mode, therefore the LOLIRQ bit has no effect in bypass mode. See
0 Ignore loss-of-lock. Interrupt not requested.
1 Enable interrupt request upon loss-of-lock.
12
LOCIRQ
Loss-of-clock interrupt request. The LOCIRQ bit enables a loss-of-clock interrupt request when the LOCF flag is
set. If either LOCF or LOCIRQ is negated, the interrupt request is negated. If loss-of-clock is detected while in
bypass mode, a system reset is generated. Therefore, LOCIRQ has no effect in bypass mode. See
“Loss-of-Clock Interrupt Request
.
0 Ignore loss-of-clock. Interrupt not requested.
1 Enable interrupt request upon loss-of-clock.
13–29
Reserved, should be cleared.
30–31
ERFD
Enhanced reduced frequency divider. This 2-bit field controls a divider at the output of the FMPLL. The value
specified by the ERFD bits establishes the division factor applied to the FMPLL frequency.
00 Divide by 2
01 Divide by 4
10 Divide by 8
11 Divide by 16
Table 17-9. ESYNCR2 Field Descriptions (continued)
Field
Description