3-34
Intel® PXA255 Processor
Developer’s Manual
Clocks and Power Manager
3.6
Clocks Manager Registers
The Clocks Manager contains three registers:
•
Core Clock Configuration Register (CCCR)
•
Clock Enable Register (CKEN)
•
Oscillator Configuration Register (OSCC)
3.6.1
Core Clock Configuration Register (CCCR)
The CCCR, shown in
Table 3-20
, controls the core clock frequency, from which the core, memory
controller, LCD controller, and DMA controller frequencies are derived. The crystal frequency to
memory frequency multiplier (L), memory frequency to run mode frequency multiplier (M), and
run mode frequency to turbo mode frequency multiplier (N) are set in this register. The clock
frequencies are shown below.
Table 3-19. RCSR Bit Definitions
0x40F0_0030
RCSR
Clocks and Power Manager
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
reserved
GP
R
SM
R
WD
R
HW
R
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1
Bits
Name
Description
[31:4]
—
reserved
3
GPR
GPIO Reset.
0 – GPIO reset has not occurred since the last time the CPU or hardware reset cleared
this bit.
1 – GPIO reset has occurred since the last time the CPU or hardware reset cleared this
bit.
Cleared by hardware reset and by setting to a 1.
2
SMR
Sleep Mode.
0 – Sleep mode has not occurred since the last time the CPU or hardware reset cleared
this bit.
1 – Sleep mode has occurred since the last time the CPU or hardware reset cleared
this bit.
Cleared by hardware reset and by setting to a 1.
1
WDR
Watchdog Reset.
0 – Watchdog reset has not occurred since the last time the CPU or hardware reset
cleared this bit.
1 – Watchdog reset has occurred since the last time the CPU or hardware reset cleared
this bit.
Cleared by hardware reset and by setting to a 1.
0
HWR
Hardware Reset.
0 – Hardware reset has not occurred since the last time the CPU cleared this bit.
1 – Hardware reset has occurred since the last time the CPU cleared this bit.
Set by hardware reset. Cleared by setting to a 1.
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......