Freescale Semiconductor MPC5200B ユーザーズマニュアル
MPC5200B Users Guide, Rev. 1
5-16
Freescale Semiconductor
CDM Registers
5.5.6
CDM Clock Enable Register—MBAR + 0x0214
The CDM Clock Enable Register, or power management register, contains control bits that enable/disable peripheral clocks. Unused
peripherals can have their clock stopped, reducing power consumption.
peripherals can have their clock stopped, reducing power consumption.
Bit
Name
Description
0–4
—
Reserved for future use. Write 0.
5
ext_usb_sync_en
Enable the synchronization logic which synchronize the external ext_usb_48Mhz
clock to the internal clock system.
clock to the internal clock system.
bit=1:ext USB 48MHz clock is synchronized to the internal clock system.
bit=0:ext USB 48MHz clock is not synchronized to the internal clock system.
6
ext_usb_48MHz_en
USB External 48MHz Clock Select
bit=1:USB 48MHz clock tree sourced from external clock from GPIO.
bit=0:USB 48MHz clock tree sourced from CDM Fractional Divider.
7
ext_irda_48MHz_en
IrDA (PSC6) External 48MHz Clock Select
bit=1:IRDA 48MHz clock tree sourced from external clock from GPIO.
bit=0:IRDA 48MHz clock tree sourced from CDM Fractional Divider.
8–14
—
Reserved for future use. Write 0.
15
fd_en
CDM 48MHz Fractional Divider Enable
bit=1:enable CDM Fractional Divider.
bit=0:disable CDM Fractional Divider.
16
—
These fields hold 4 phase divide ratios used by the fractional divider. The fields are
incompletely decoded; f
incompletely decoded; f
system
/11 is obtained with 3 values.
110–fractional counter divide ratio
f
system
/6
111–fractional counter divide ratio
f
system
/7
000–fractional counter divide ratio
f
system
/8
001–fractional counter divide ratio
f
system
/9
010–fractional counter divide ratio
f
system
/10
011–fractional counter divide ratio
f
system
/11
10X–fractional counter divide ratio
f
system
/11
17–19
cgfd_p3_cnt[2:0]
20
—
21–23
cgfd_p2_cnt[2:0]
24
—
25–27
cgfd_p1_cnt[2:0]
28
—
29–31
cgfd_p0_cnt[2:0]
Table 5-13. CDM Clock Enable Register
msb 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
Reserved
Write 0
mem_
clk_en
pci_
clk_en
lpc
_
clk_en
sl
t_
clk_en
W
RESET:
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 lsb
R
scom_
cl
k_en
ata_
cl
k_en
eth_
cl
k_en
usb_
cl
k_en
spi_
cl
k_en
bdl
c_c
lk_
en
psc5_
cl
k_en
psc4_
cl
k_en
psc3_
cl
k_en
psc2_
cl
k_en
psc1_
cl
k_en
psc6
cl
k_en
msc
a
n_
cl
k_en
i2c_
cl
k_en
timer
_
cl
k_en
gpio_
cl
k_en
W
RESET:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1