lxdream 0.9.1| filename | test/timer.c |
| changeset | 731:ee2e929cca3a |
| prev | 272:fb6be85235e8 |
| author | nkeynes |
| date | Wed Nov 10 08:37:42 2010 +1000 (13 years ago) |
| permissions | -rw-r--r-- |
| last change | Add chain pointer to the xlat cache, so that we can maintain multiple blocks for the same address. This prevents thrashing in cases where we would other keep retranslating the same blocks over and over again due to varying xlat_sh4_mode values |
| view | annotate | diff | log | raw |
1 #include "lib.h"
2 #define TMU_CHANNEL 2
3 #define BASE_TICKS_PER_US 200
4 #define CLOCK_DIVIDER 16
5 #define TOCR 0xFFD80000 /* Output control register */
6 #define TSTR 0xFFD80004 /* Start register */
7 #define TCOR(c) (0xFFD80008 + (c*12)) /* Constant register */
8 #define TCNT(c) (0xFFD8000C + (c*12)) /* Count register */
9 #define TCR(c) (0xFFD80010 + (c*12)) /* Control register */
11 /**
12 * Initialize the on-chip timer controller. We snag TMU channel 2 in its
13 * highest resolution mode, and start it counting down from max_int.
14 */
15 void timer_init() {
16 unsigned int val = byte_read(TSTR);
17 byte_write( TSTR, val & (~(1<<TMU_CHANNEL)) ); /* Stop counter */
18 long_write( TCOR(TMU_CHANNEL), 0xFFFFFFFF );
19 long_write( TCNT(TMU_CHANNEL), 0xFFFFFFFF );
20 word_write( TCR(TMU_CHANNEL), 0x00000000 );
21 }
23 void timer_run() {
24 byte_write( TSTR, byte_read(TSTR) | (1<<TMU_CHANNEL) );
25 }
27 void timer_start() {
28 timer_init();
29 timer_run();
30 }
32 /**
33 * Report the current value of TMU2.
34 */
35 unsigned int timer_gettime() {
36 return long_read(TCNT(TMU_CHANNEL));
37 }
39 /**
40 * Stop TMU2 and report the current value.
41 */
42 unsigned int timer_stop() {
43 long_write( TSTR, long_read(TSTR) & (~(1<<TMU_CHANNEL)) );
44 return long_read( TCNT(TMU_CHANNEL) );
45 }
48 /**
49 * Convert the supplied timer value to a number of micro seconds since the timer
50 * was started.
51 */
52 unsigned int timer_to_microsecs( unsigned int value ) {
53 return (0xFFFFFFFF - value) * CLOCK_DIVIDER / BASE_TICKS_PER_US;
54 }
56 unsigned int timer_gettime_us() {
57 return timer_to_microsecs( timer_gettime() );
58 }
.