Information

41.4.2 Clock register (USBDCD_CLOCK)
Address: USBDCD_CLOCK is 4003_5000h base + 4h offset = 4003_5004h
Bit 31 30 29 28 27 26 25 24
R
0
W
Reset
0 0 0 0 0 0 0 0
Bit
23 22 21 20 19 18 17 16
R
0
W
Reset
0 0 0 0 0 0 0 0
Bit
15 14 13 12 11 10 9 8
R
0
CLOCK_SPEED[2:6]
W
Reset
0 0 0 0 0 0 0 0
Bit
7 6 5 4 3 2 1 0
R
CLOCK_SPEED[5:0]
0 CLOCK_
UNIT
W
Reset
1 1 0 0 0 0 0 1
USBDCD_CLOCK field descriptions
Field Description
31–12
Reserved
This read-only field is reserved and always has the value zero.
11–2
CLOCK_SPEED
Numerical Value of Clock Speed in Binary
The unit of measure is programmed in CLOCK_UNIT. The valid range is from 1 to 1023 when clock unit is
MHz and 4 to 1023 when clock unit is kHz. Examples with CLOCK_UNIT = 1:
• For 48 MHz: 0b00_0011_0000 (48) (Default)
• For 24 MHz: 0b00_0001_1000 (24)
Examples with CLOCK_UNIT = 0:
• For 100 kHz: 0b00_0110_0100 (100)
• For 500 kHz: 0b01_1111_0100 (500)
1
Reserved
This read-only field is reserved and always has the value zero.
0
CLOCK_UNIT
Unit of Measurement Encoding for Clock Speed
Specifies the unit of measure for the clock speed.
0 kHz Speed (between 1 kHz and 1023 kHz)
1 MHz Speed (between 1 MHz and 1023 MHz)
Memory map/Register definition
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
932 Freescale Semiconductor, Inc.