PXD20RM Datasheet, PDF (256/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

Table 8-58. Interrupt Status Register (CMU_ISR) field descriptions (continued)
30
FLLI
31
OLRI
FMPLL0 Clock frequency less than low reference event
This bit is set by hardware when CK_FMPLL frequency becomes lower than LFREF value
and CK_FMPLL is ‘ON’ as signalled by the MC_ME. It can be cleared by software by
writing ‘1’.
0: No FLL event.
1: FLL event is pending.
Oscillator frequency less than RC frequency event
This bit is set by hardware when the frequency of CK_FXOSC is less than
CK_FIRC/2^RCDIV frequency and CK_FXOSC is ‘ON’ as signalled by the MC_ME. It can be
cleared by software by writing ‘1’.
0: No OLR event.
1: OLR event is pending.
8.7.4.6 Measurement Duration Register (CMU_MDR)
Address offset: 0x18
Reset value: 0x00000000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
reserved
MD[19:16]
r
rw
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
MD[15:0]
rw
Table 8-59. Measurement Duration Register (CMU_MDR)
Table 8-60. Measurement Duration Register (CMU_MDR) field descriptions
Field
12-31
MD
Description
Measurement duration bits
This register displays the measured duration in term of IRC clock cycles. This value is
loaded in the frequency meter downcounter. When SFM bit is set to ‘1’, downcounter
starts counting.
8.7.5 Functional description
The names of the clocks involved in this block have the following meaning:
• CK_FXOSC: clock coming from the external crystal oscillator.
• CK_SIRC: clock coming from the low frequency internal RC oscillator.
• CK_FIRC: clock coming from the high frequency internal RC oscillator.
• CK_PLL: clock coming from the PLL.
• FOSC: frequency of external crystal oscillator clock.
• FRCslow: frequency of low frequency internal RC oscillator.
8-60
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
Freescale Semiconductor