6 cdm clock enable register-mbar + 0x0214, Section 5.5.6, Cdm clock enable register—mbar + 0x0214 – Freescale Semiconductor MPC5200B User Manual

Page 149: Cdm clock enable register

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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.

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.

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

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

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