| wdenk | 756f586 | 2005-04-03 15:51:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2000 |
| 3 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
| 24 | /*----------------------------------------------------------------------- |
| 25 | * Timer value for timer 2, ICLK = 10 |
| 26 | * |
| 27 | * SPEED_FCOUNT2 = GCLK / (16 * (TIMER_TMR_PS + 1)) |
| 28 | * SPEED_TMR3_PS = (GCLK / (16 * SPEED_FCOUNT3)) - 1 |
| 29 | * |
| 30 | * SPEED_FCOUNT2 timer 2 counting frequency |
| 31 | * GCLK CPU clock |
| 32 | * SPEED_TMR2_PS prescaler |
| 33 | */ |
| 34 | #define SPEED_TMR2_PS (250 - 1) /* divide by 250 */ |
| 35 | |
| 36 | /*----------------------------------------------------------------------- |
| 37 | * Timer value for PIT |
| 38 | * |
| 39 | * PIT_TIME = SPEED_PITC / PITRTCLK |
| 40 | * PITRTCLK = 8192 |
| 41 | */ |
| 42 | #define SPEED_PITC (82 << 16) /* start counting from 82 */ |
| 43 | |
| 44 | /* |
| 45 | * The new value for PTA is calculated from |
| 46 | * |
| 47 | * PTA = (gclk * Trefresh) / (2 ^ (2 * DFBRG) * PTP * NCS) |
| 48 | * |
| 49 | * gclk CPU clock (not bus clock !) |
| 50 | * Trefresh Refresh cycle * 4 (four word bursts used) |
| 51 | * DFBRG For normal mode (no clock reduction) always 0 |
| 52 | * PTP Prescaler (already adjusted for no. of banks and 4K / 8K refresh) |
| 53 | * NCS Number of SDRAM banks (chip selects) on this UPM. |
| 54 | */ |