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Update clock logic

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2576 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2010-04-07 03:00:34 +00:00
parent 47e6e99533
commit 5cca859e00
1 changed files with 22 additions and 0 deletions
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22
configs/sam3u-ek/include/board.h
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@ -87,6 +87,28 @@
#define SAM3U_PLLA_FREQUENCY (96000000)
#define SAM3U_CPU_FREQUENCY (48000000)
/* HSMCI clocking
*
* Multimedia Card Interface clock (MCCK or MCI_CK) is Master Clock (MCK)
* divided by (2*(CLKDIV+1)).
*
* MCI_SPEED = MCK / (2*(CLKDIV+1))
* CLKDIV = MCI / MCI_SPEED / 2 - 1
*/
/* MCK = 48MHz, CLKDIV = 59, MCI_SPEED = 48MHz / 2 * (59+1) = 400 KHz */
#define HSMCI_INIT_CLKDIV (59 << HSMCI_MR_CLKDIV_SHIFT)
/* MCK = 48MHz, CLKDIV = 1, MCI_SPEED = 48MHz / 2 * (1+1) = 12 MHz */
#define HSMCI_MMCXFR_CLKDIV (3 << HSMCI_MR_CLKDIV_SHIFT)
/* MCK = 48MHz, CLKDIV = 0, MCI_SPEED = 48MHz / 2 * (0+1) = 24 MHz */
#define HSMCI_SDXFR_CLKDIV (0 << HSMCI_MR_CLKDIV_SHIFT)
#define HSMCI_SDWIDEXFR_CLKDIV HSMCI_SDXFR_CLKDIV
/* LED definitions ******************************************************************/
#define LED_STARTED 0 /* LED0=OFF LED1=OFF LED2=OFF */