1 /******************************************************************************
2 *  Filename:       cpu.h
3 *
4 *  Description:    Defines and prototypes for the CPU instruction wrapper
5 *                  functions.
6 *
7 *  Copyright (c) 2015 - 2022, Texas Instruments Incorporated
8 *  All rights reserved.
9 *
10 *  Redistribution and use in source and binary forms, with or without
11 *  modification, are permitted provided that the following conditions are met:
12 *
13 *  1) Redistributions of source code must retain the above copyright notice,
14 *     this list of conditions and the following disclaimer.
15 *
16 *  2) Redistributions in binary form must reproduce the above copyright notice,
17 *     this list of conditions and the following disclaimer in the documentation
18 *     and/or other materials provided with the distribution.
19 *
20 *  3) Neither the name of the ORGANIZATION nor the names of its contributors may
21 *     be used to endorse or promote products derived from this software without
22 *     specific prior written permission.
23 *
24 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
28 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 *  POSSIBILITY OF SUCH DAMAGE.
35 *
36 ******************************************************************************/
37 
38 //*****************************************************************************
39 //
40 //! \addtogroup system_cpu_group
41 //! @{
42 //! \addtogroup cpu_api
43 //! @{
44 //
45 //*****************************************************************************
46 
47 #ifndef __CPU_H__
48 #define __CPU_H__
49 
50 //*****************************************************************************
51 //
52 // If building with a C++ compiler, make all of the definitions in this header
53 // have a C binding.
54 //
55 //*****************************************************************************
56 #ifdef __cplusplus
57 extern "C"
58 {
59 #endif
60 
61 #include <stdbool.h>
62 #include <stdint.h>
63 #include "../inc/hw_types.h"
64 #include "../inc/hw_memmap.h"
65 #include "../inc/hw_cpu_scs.h"
66 
67 //*****************************************************************************
68 //
69 // Support for DriverLib in ROM:
70 // This section renames all functions that are not "static inline", so that
71 // calling these functions will default to implementation in flash. At the end
72 // of this file a second renaming will change the defaults to implementation in
73 // ROM for available functions.
74 //
75 // To force use of the implementation in flash, e.g. for debugging:
76 // - Globally: Define DRIVERLIB_NOROM at project level
77 // - Per function: Use prefix "NOROM_" when calling the function
78 //
79 //*****************************************************************************
80 #if !defined(DOXYGEN)
81     #define CPUcpsid                        NOROM_CPUcpsid
82     #define CPUprimask                      NOROM_CPUprimask
83     #define CPUcpsie                        NOROM_CPUcpsie
84     #define CPUbasepriGet                   NOROM_CPUbasepriGet
85     #define CPUdelay                        NOROM_CPUdelay
86 #endif
87 
88 //*****************************************************************************
89 //
90 // API Functions and prototypes
91 //
92 //*****************************************************************************
93 
94 //*****************************************************************************
95 //
96 //! \brief Disable all external interrupts.
97 //!
98 //! Use this function to disable all system interrupts. This function is
99 //! implemented as a wrapper function for the CPSID instruction.
100 //!
101 //! \return Returns the state of \b PRIMASK on entry
102 //
103 //*****************************************************************************
104 extern uint32_t CPUcpsid(void);
105 
106 //*****************************************************************************
107 //
108 //! \brief Get the current interrupt state.
109 //!
110 //! Use this function to retrieve the current state of the interrupts. This
111 //! function is implemented as a wrapper function returning the state of
112 //! PRIMASK.
113 //!
114 //! \return Returns the state of the \b PRIMASK (indicating whether interrupts
115 //! are enabled or disabled).
116 //
117 //*****************************************************************************
118 extern uint32_t CPUprimask(void);
119 
120 //*****************************************************************************
121 //
122 //! \brief Enable all external interrupts.
123 //!
124 //! Use this function to enable all system interrupts. This function is
125 //! implemented as a wrapper function for the CPSIE instruction.
126 //!
127 //! \return Returns the state of \b PRIMASK on entry.
128 //
129 //*****************************************************************************
130 extern uint32_t CPUcpsie(void);
131 
132 //*****************************************************************************
133 //
134 //! \brief Get the interrupt priority disable level.
135 //!
136 //! Use this function to get the level of priority that will disable
137 //! interrupts with a lower priority level.
138 //!
139 //! \return Returns the value of the \b BASEPRI register.
140 //
141 //*****************************************************************************
142 extern uint32_t CPUbasepriGet(void);
143 
144 //*****************************************************************************
145 //
146 //! \brief Provide a small non-zero delay using a simple loop counter.
147 //!
148 //! This function provides means for generating a constant length delay. It
149 //! is written in assembly to keep the delay consistent across tool chains,
150 //! avoiding the need to tune the delay based on the tool chain in use.
151 //!
152 //! \note It is not recommended using this function for long delays.
153 //!
154 //! Notice that interrupts can affect the delay if not manually disabled in advance.
155 //!
156 //! The delay depends on where code resides and the path for code fetching:
157 //! - Code in flash, cache enabled, prefetch enabled  : 4 cycles per loop (Default)
158 //! - Code in flash, cache enabled, prefetch disabled : 5 cycles per loop
159 //! - Code in flash, cache disabled                   : 7 cycles per loop
160 //! - Code in SRAM                                    : 6 cycles per loop
161 //! - Code in GPRAM                                   : 3 cycles per loop
162 //!
163 //! \note If using an RTOS, consider using RTOS provided delay functions because
164 //! these will not block task scheduling and will potentially save power.
165 //!
166 //! Calculate delay count based on the wanted delay in microseconds (us):
167 //! - ui32Count = [delay in us] * [CPU clock in MHz] / [cycles per loop]
168 //!
169 //! Example: 250 us delay with code in flash and with cache and prefetch enabled:
170 //! - ui32Count = 250 * 48 / 4 = 3000
171 //!
172 //! \param ui32Count is the number of delay loop iterations to perform. Number must be greater than zero.
173 //!
174 //! \return None
175 //
176 //*****************************************************************************
177 extern void CPUdelay(uint32_t ui32Count);
178 
179 //*****************************************************************************
180 //
181 //! \brief Wait for interrupt.
182 //!
183 //! Use this function to let the System CPU wait for the next interrupt. This
184 //! function is implemented as a wrapper function for the WFI instruction.
185 //!
186 //! \return None
187 //
188 //*****************************************************************************
189 #if defined(DOXYGEN)
190 __STATIC_INLINE void
CPUwfi(void)191 CPUwfi(void)
192 {
193     // This function is written in assembly. See cpu.h for compiler specific implementation.
194 }
195 #elif defined(__IAR_SYSTEMS_ICC__)
196 __STATIC_INLINE void
CPUwfi(void)197 CPUwfi(void)
198 {
199     // Wait for the next interrupt.
200     __asm("    wfi\n");
201 }
202 #elif defined(__CC_ARM) || defined(__ARMCC_VERSION)
203 __asm __STATIC_INLINE void
CPUwfi(void)204 CPUwfi(void)
205 {
206     // Wait for the next interrupt.
207     wfi;
208     bx      lr
209 }
210 #elif defined(__TI_COMPILER_VERSION__)
211 __STATIC_INLINE void
CPUwfi(void)212 CPUwfi(void)
213 {
214     // Wait for the next interrupt.
215     __asm("    wfi\n");
216 }
217 #else
218 __STATIC_INLINE void __attribute__((always_inline))
CPUwfi(void)219 CPUwfi(void)
220 {
221     // Wait for the next interrupt.
222     __asm volatile ("    wfi\n");
223 }
224 #endif
225 
226 //*****************************************************************************
227 //
228 //! \brief Wait for event.
229 //!
230 //! Use this function to let the System CPU wait for the next event. This
231 //! function is implemented as a wrapper function for the WFE instruction.
232 //!
233 //! \return None
234 //
235 //*****************************************************************************
236 #if defined(DOXYGEN)
237 __STATIC_INLINE void
CPUwfe(void)238 CPUwfe(void)
239 {
240     // This function is written in assembly. See cpu.h for compiler specific implementation.
241 }
242 #elif defined(__IAR_SYSTEMS_ICC__)
243 __STATIC_INLINE void
CPUwfe(void)244 CPUwfe(void)
245 {
246     // Wait for the next event.
247     __asm("    wfe\n");
248 }
249 #elif defined(__CC_ARM) || defined(__ARMCC_VERSION)
250 __asm __STATIC_INLINE void
CPUwfe(void)251 CPUwfe(void)
252 {
253     // Wait for the next event.
254     wfe;
255     bx      lr
256 }
257 #elif defined(__TI_COMPILER_VERSION__)
258 __STATIC_INLINE void
CPUwfe(void)259 CPUwfe(void)
260 {
261     // Wait for the next event.
262     __asm("    wfe\n");
263 }
264 #else
265 __STATIC_INLINE void __attribute__((always_inline))
CPUwfe(void)266 CPUwfe(void)
267 {
268     // Wait for the next event.
269     __asm volatile ("    wfe\n");
270 }
271 #endif
272 
273 //*****************************************************************************
274 //
275 //! \brief Send event.
276 //!
277 //! Use this function to let the System CPU send an event. This function is
278 //! implemented as a wrapper function for the SEV instruction.
279 //!
280 //! \return None
281 //
282 //*****************************************************************************
283 #if defined(DOXYGEN)
284 __STATIC_INLINE void
CPUsev(void)285 CPUsev(void)
286 {
287     // This function is written in assembly. See cpu.h for compiler specific implementation.
288 }
289 #elif defined(__IAR_SYSTEMS_ICC__)
290 __STATIC_INLINE void
CPUsev(void)291 CPUsev(void)
292 {
293     // Send event.
294     __asm("    sev\n");
295 }
296 #elif defined(__CC_ARM) || defined(__ARMCC_VERSION)
297 __asm __STATIC_INLINE void
CPUsev(void)298 CPUsev(void)
299 {
300     // Send event.
301     sev;
302     bx      lr
303 }
304 #elif defined(__TI_COMPILER_VERSION__)
305 __STATIC_INLINE void
CPUsev(void)306 CPUsev(void)
307 {
308     // Send event.
309     __asm("    sev\n");
310 }
311 #else
312 __STATIC_INLINE void __attribute__((always_inline))
CPUsev(void)313 CPUsev(void)
314 {
315     // Send event.
316     __asm volatile ("    sev\n");
317 }
318 #endif
319 
320 //*****************************************************************************
321 //
322 //! \brief Update the interrupt priority disable level.
323 //!
324 //! Use this function to change the level of priority that will disable
325 //! interrupts with a lower priority level.
326 //!
327 //! \param ui32NewBasepri is the new basis priority level to set.
328 //!
329 //! \return None
330 //
331 //*****************************************************************************
332 #if defined(DOXYGEN)
333 __STATIC_INLINE void
CPUbasepriSet(uint32_t ui32NewBasepri)334 CPUbasepriSet(uint32_t ui32NewBasepri)
335 {
336     // This function is written in assembly. See cpu.h for compiler specific implementation.
337 }
338 #elif defined(__IAR_SYSTEMS_ICC__)
339 __STATIC_INLINE void
CPUbasepriSet(uint32_t ui32NewBasepri)340 CPUbasepriSet(uint32_t ui32NewBasepri)
341 {
342     // Set the BASEPRI register.
343     __asm("    msr     BASEPRI, r0\n");
344 }
345 #elif defined(__CC_ARM) || defined(__ARMCC_VERSION)
346 __asm __STATIC_INLINE void
CPUbasepriSet(uint32_t ui32NewBasepri)347 CPUbasepriSet(uint32_t ui32NewBasepri)
348 {
349     // Set the BASEPRI register.
350     msr     BASEPRI, r0;
351     bx      lr
352 }
353 #elif (defined(__TI_COMPILER_VERSION__) || defined(__clang__))
354 __STATIC_INLINE void
CPUbasepriSet(uint32_t ui32NewBasepri)355 CPUbasepriSet(uint32_t ui32NewBasepri)
356 {
357     // Set the BASEPRI register.
358     __asm("    msr     BASEPRI, r0\n");
359 }
360 #else
361 #pragma GCC diagnostic push
362 #pragma GCC diagnostic ignored "-Wattributes"
363 __STATIC_INLINE void __attribute__ ((naked))
CPUbasepriSet(uint32_t ui32NewBasepri)364 CPUbasepriSet(uint32_t ui32NewBasepri)
365 {
366     // Set the BASEPRI register.
367     __asm volatile ("    msr     BASEPRI, %0\n"
368                     "    bx      lr\n"
369                     : /* No output */
370                     : "r" (ui32NewBasepri)
371                    );
372 }
373 #pragma GCC diagnostic pop
374 #endif
375 
376 //*****************************************************************************
377 //
378 //! \brief Disable CPU write buffering (recommended for debug purpose only).
379 //!
380 //! This function helps debugging "bus fault crashes".
381 //! Disables write buffer use during default memory map accesses.
382 //!
383 //! This causes all bus faults to be precise bus faults but decreases the
384 //! performance of the processor because the stores to memory have to complete
385 //! before the next instruction can be executed.
386 //!
387 //! \return None
388 //!
389 //! \sa \ref CPU_WriteBufferEnable()
390 //
391 //*****************************************************************************
392 __STATIC_INLINE void
CPU_WriteBufferDisable(void)393 CPU_WriteBufferDisable( void )
394 {
395     HWREGBITW( CPU_SCS_BASE + CPU_SCS_O_ACTLR, CPU_SCS_ACTLR_DISDEFWBUF_BITN ) = 1;
396 }
397 
398 //*****************************************************************************
399 //
400 //! \brief Enable CPU write buffering (default setting).
401 //!
402 //! Re-enables write buffer during default memory map accesses if
403 //! \ref CPU_WriteBufferDisable() has been used for bus fault debugging.
404 //!
405 //! \return None
406 //!
407 //! \sa \ref CPU_WriteBufferDisable()
408 //
409 //*****************************************************************************
410 __STATIC_INLINE void
CPU_WriteBufferEnable(void)411 CPU_WriteBufferEnable( void )
412 {
413     HWREGBITW( CPU_SCS_BASE + CPU_SCS_O_ACTLR, CPU_SCS_ACTLR_DISDEFWBUF_BITN ) = 0;
414 }
415 
416 //*****************************************************************************
417 //
418 // Support for DriverLib in ROM:
419 // Redirect to implementation in ROM when available.
420 //
421 //*****************************************************************************
422 #if !defined(DRIVERLIB_NOROM) && !defined(DOXYGEN)
423     #include "../driverlib/rom.h"
424     #ifdef ROM_CPUcpsid
425         #undef  CPUcpsid
426         #define CPUcpsid                        ROM_CPUcpsid
427     #endif
428     #ifdef ROM_CPUprimask
429         #undef  CPUprimask
430         #define CPUprimask                      ROM_CPUprimask
431     #endif
432     #ifdef ROM_CPUcpsie
433         #undef  CPUcpsie
434         #define CPUcpsie                        ROM_CPUcpsie
435     #endif
436     #ifdef ROM_CPUbasepriGet
437         #undef  CPUbasepriGet
438         #define CPUbasepriGet                   ROM_CPUbasepriGet
439     #endif
440     #ifdef ROM_CPUdelay
441         #undef  CPUdelay
442         #define CPUdelay                        ROM_CPUdelay
443     #endif
444 #endif
445 
446 //*****************************************************************************
447 //
448 // Mark the end of the C bindings section for C++ compilers.
449 //
450 //*****************************************************************************
451 #ifdef __cplusplus
452 }
453 #endif
454 
455 #endif // __CPU_H__
456 
457 //*****************************************************************************
458 //
459 //! Close the Doxygen group.
460 //! @}
461 //! @}
462 //
463 //*****************************************************************************
464