55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
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/*
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* (C) Copyright 2000
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* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*-----------------------------------------------------------------------
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* Timer value for timer 2, ICLK = 10
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*
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* SPEED_FCOUNT2 = GCLK / (16 * (TIMER_TMR_PS + 1))
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* SPEED_TMR3_PS = (GCLK / (16 * SPEED_FCOUNT3)) - 1
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*
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* SPEED_FCOUNT2 timer 2 counting frequency
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* GCLK CPU clock
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* SPEED_TMR2_PS prescaler
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*/
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#define SPEED_TMR2_PS (250 - 1) /* divide by 250 */
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/*-----------------------------------------------------------------------
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* Timer value for PIT
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*
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* PIT_TIME = SPEED_PITC / PITRTCLK
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* PITRTCLK = 8192
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*/
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#define SPEED_PITC (82 << 16) /* start counting from 82 */
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/*
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* The new value for PTA is calculated from
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*
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* PTA = (gclk * Trefresh) / (2 ^ (2 * DFBRG) * PTP * NCS)
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*
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* gclk CPU clock (not bus clock !)
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* Trefresh Refresh cycle * 4 (four word bursts used)
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* DFBRG For normal mode (no clock reduction) always 0
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* PTP Prescaler (already adjusted for no. of banks and 4K / 8K refresh)
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* NCS Number of SDRAM banks (chip selects) on this UPM.
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*/
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