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author | root <root@artemis.panaceas.org> | 2016-09-06 14:29:07 +0100 |
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committer | root <root@artemis.panaceas.org> | 2016-09-06 14:29:07 +0100 |
commit | 090d8a264d52dd03b66511cba413819ed2316ea8 (patch) | |
tree | 718be9cc872bb30d51aa97865d5887ca6e8b6ab0 | |
parent | 4832b89fb04ac44630cae5ded2a87e5354e40434 (diff) | |
download | stm32_usb_kvm-090d8a264d52dd03b66511cba413819ed2316ea8.tar.gz stm32_usb_kvm-090d8a264d52dd03b66511cba413819ed2316ea8.tar.bz2 stm32_usb_kvm-090d8a264d52dd03b66511cba413819ed2316ea8.zip |
fish
-rw-r--r-- | app/ticker.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/app/ticker.c b/app/ticker.c new file mode 100644 index 0000000..efcbda6 --- /dev/null +++ b/app/ticker.c @@ -0,0 +1,86 @@ +#include "project.h" + + +static volatile uint32_t delay_ms_count; +volatile uint32_t ticks; +static uint32_t scale = 7; + +void +delay_us (uint32_t d) +{ + d *= scale; + while (d--) + { + __asm__ ("nop"); + } +} + + +void +sys_tick_handler (void) +{ + uint8_t d; + + if (delay_ms_count) + delay_ms_count--; + + ticks++; + + while (!ring_read_byte (&rx1_ring, &d)) + kvm_recv (d); + + while (!ring_read_byte (&rx2_ring, &d)) + kvm_recv (d); + + led_tick (); +} + + +void +delay_ms (uint32_t d) +{ + delay_ms_count = d; + while (delay_ms_count); +} + +int +timed_out (uint32_t then, unsigned int ms) +{ + then = ticks - then; + + if (then > ms) + return 1; + return 0; +} + + +void +ticker_init (void) +{ + uint32_t v, w; + + /*Start periodic timer */ + + systick_set_clocksource (STK_CSR_CLKSOURCE_AHB_DIV8); + /* 48MHz / 8 = > 6Mhz */ + systick_set_reload (6000); + /* 6MHz / 6000 => 1kHz */ + systick_interrupt_enable (); + systick_counter_enable (); + + + /*Calibrate the delay loop */ + do + { + scale--; + v = ticks; + while (v == ticks); + delay_us (1000); + w = ticks; + v++; + w -= v; + } + while (w); + + +} |