1 #error This code must be revised for the new timer API
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30 * Copyright 2004 Develer S.r.l. (http://www.develer.com/)
31 * Copyright 2004 Giovanni Bajo
36 * \author Giovanni Bajo <rasky@develer.com>
38 * \brief Driver module for DSP56K
43 *#* Revision 1.10 2006/07/19 12:56:26 bernie
44 *#* Convert to new Doxygen style.
46 *#* Revision 1.9 2006/02/21 21:28:02 bernie
47 *#* New time handling based on TIMER_TICKS_PER_SEC to support slow timers with ticks longer than 1ms.
49 *#* Revision 1.8 2005/11/04 16:20:02 bernie
50 *#* Fix reference to README.devlib in header.
52 *#* Revision 1.7 2005/04/11 19:10:28 bernie
53 *#* Include top-level headers from cfg/ subdir.
55 *#* Revision 1.6 2004/11/16 22:37:14 bernie
56 *#* Replace IPTR with iptr_t.
58 *#* Revision 1.5 2004/08/25 14:12:08 rasky
59 *#* Aggiornato il comment block dei log RCS
61 *#* Revision 1.4 2004/07/30 14:27:49 rasky
62 *#* Aggiornati alcuni file DSP56k per la nuova libreria di IRQ management
64 *#* Revision 1.3 2004/06/06 18:30:34 bernie
65 *#* Import DSP56800 changes from SC.
67 *#* Revision 1.2 2004/06/03 11:27:09 bernie
68 *#* Add dual-license information.
70 *#* Revision 1.1 2004/05/23 18:23:30 bernie
71 *#* Import drv/timer module.
75 #ifndef DRV_TIMER_DSP56K_H
76 #define DRV_TIMER_DSP56K_H
79 #include <DSP56F807.h>
80 #include <cfg/compiler.h>
84 // Calculate register pointer and irq vector from hw.h setting
85 #define REG_SYSTEM_TIMER PP_CAT(REG_TIMER_, SYSTEM_TIMER)
86 #define SYSTEM_TIMER_IRQ_VECTOR PP_CAT(IRQ_TIMER_, SYSTEM_TIMER)
88 /// Prescaler for the system timer
89 #define TIMER_PRESCALER 16
91 /// Frequency of the hardware high precision timer
92 #define TIMER_HW_HPTICKS_PER_SEC (IPBUS_FREQ / TIMER_PRESCALER)
94 /// Type of time expressed in ticks of the hardware high precision timer
95 typedef uint16_t hptime_t;
97 static void system_timer_isr(UNUSED(iptr_t, arg));
99 static void timer_hw_init(void)
103 // Clear compare flag status and enable interrupt on compare
104 REG_SYSTEM_TIMER->SCR &= ~REG_TIMER_SCR_TCF;
105 REG_SYSTEM_TIMER->SCR |= REG_TIMER_SCR_TCFIE;
107 // Calculate the compare value needed to generate an interrupt exactly
108 // TICKS_PER_SEC times each second (usually, every millisecond). Check that
109 // the calculation is accurate, otherwise there is a precision error
110 // (probably the prescaler is too big or too small).
111 compare = TIMER_HW_HPTICKS_PER_SEC / TICKS_PER_SEC;
112 ASSERT((uint32_t)compare * TICKS_PER_SEC == IPBUS_FREQ / TIMER_PRESCALER);
113 REG_SYSTEM_TIMER->CMP1 = compare;
115 // The value for reload (at initializationa and after compare is met) is zero
116 REG_SYSTEM_TIMER->LOAD = 0;
118 // Set the interrupt handler and priority
119 irq_install(SYSTEM_TIMER_IRQ_VECTOR, &system_timer_isr, NULL);
120 irq_setpriority(SYSTEM_TIMER_IRQ_VECTOR, IRQ_PRIORITY_SYSTEM_TIMER);
122 // Small preprocessor trick to generate the REG_TIMER_CTRL_PRIMARY_IPBYNN macro
123 // needed to set the prescaler
124 #define REG_CONTROL_PRESCALER PP_CAT(REG_TIMER_CTRL_PRIMARY_IPBY, TIMER_PRESCALER)
126 // Setup the counter and start counting
127 REG_SYSTEM_TIMER->CTRL =
128 REG_TIMER_CTRL_MODE_RISING | // count rising edges (normal)
129 REG_CONTROL_PRESCALER | // frequency (IPbus / TIMER_PRESCALER)
130 REG_TIMER_CTRL_LENGTH; // up to CMP1, then reload
133 INLINE void timer_hw_irq(void)
135 // Clear the overflow flag so that we are ready for another interrupt
136 REG_SYSTEM_TIMER->SCR &= ~REG_TIMER_SCR_TCF;
139 INLINE hptime_t timer_hw_hpread(void)
141 return REG_SYSTEM_TIMER->CNTR;
144 #define DEFINE_TIMER_ISR \
145 static void system_timer_isr(UNUSED(iptr_t, arg))
147 #endif /* DRV_TIMER_DSP56_H */