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Fix the delay loops. Without scaling the CPU is always at 300MHz.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12229 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Marcoen Hirschberg 2007-02-08 10:21:37 +00:00
parent 6dd8fbe25d
commit e645e2dcf2
2 changed files with 4 additions and 4 deletions
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2
firmware/target/arm/gigabeat/meg-fx/i2c-meg-fx.c
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@ -90,7 +90,7 @@ static void i2c_delay(void)
/* about 30 cycles overhead + X * 7 */
/* 300MHz: 1000nS @3.36nS/cyc = 297cyc: X = 38*/
/* 100MHz: 1000nS @10nS/cyc = 100cyc : X = 10 */
for (_x = get_cpu_boost_counter() ? 38 : 10; _x; _x--)
for (_x = 38; _x; _x--)
{
/* burn CPU cycles */
/* gcc makes it an inc loop - check with objdump for asm timing */

6
firmware/target/arm/gigabeat/meg-fx/sc606-meg-fx.c
View file

@ -30,9 +30,9 @@
/* cycles delayed = 30 + 7 * loops */
/* 100MHz = 10nS per cycle: LO:1300nS=130:14 HI:600nS=60:9 */
/* 300MHz = 3.36nS per cycle: LO:1300nS=387:51 HI:600nS=179:21 */
#define DELAY_LO do{int x;for(x=get_cpu_boost_counter()?51:14;x;x--);} while (0)
#define DELAY do{int x;for(x=get_cpu_boost_counter()?35:10;x;x--);} while (0)
#define DELAY_HI do{int x;for(x=get_cpu_boost_counter()?21: 9;x;x--);} while (0)
#define DELAY_LO do{int x;for(x=51;x;x--);} while (0)
#define DELAY do{int x;for(x=35;x;x--);} while (0)
#define DELAY_HI do{int x;for(x=21;x;x--);} while (0)